builder: apply fixed offset before relative adjustments

A fixed offset (e.g. the "UTC" keyword) was applied after relative
items, so "1970/01/01 UTC N seconds" added N seconds to a local
wall-clock that could drift across a DST boundary before being
re-anchored at the offset, yielding an instant off by the DST gap.
Anchor the offset first, then apply relative items.

Fixes uutils/coreutils#12555.

.github/workflows/audit.yml

@@ -0,0 +1,15 @@
+name: Security audit
+
+on:
+  schedule:
+    - cron: "0 0 * * *"
+jobs:
+  audit:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          persist-credentials: false
+      - uses: rustsec/audit-check@v2
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/ci.yml

@@ -3,6 +3,7 @@ on: [push, pull_request]
 name: Basic CI
 
 env:
+  CARGO_INCREMENTAL: "0"
   CARGO_TERM_COLOR: always
   RUST_MIN_SRV: "1.71.1"
 
@@ -14,8 +15,7 @@ jobs:
       matrix:
         os: [ubuntu-latest, macOS-latest, windows-latest]
     steps:
-      - uses: actions/checkout@v5
-      - uses: dtolnay/rust-toolchain@stable
+      - uses: actions/checkout@v6
       - run: cargo check
 
   test:
@@ -25,17 +25,14 @@ jobs:
       matrix:
         os: [ubuntu-latest, macOS-latest, windows-latest]
     steps:
-      - uses: actions/checkout@v5
-      - uses: dtolnay/rust-toolchain@stable
+      - uses: actions/checkout@v6
       - run: cargo test
 
   fmt:
     name: cargo fmt --all -- --check
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v5
-      - uses: dtolnay/rust-toolchain@stable
-      - run: rustup component add rustfmt
+      - uses: actions/checkout@v6
       - run: cargo fmt --all -- --check
 
   clippy:
@@ -45,9 +42,7 @@ jobs:
       matrix:
         os: [ubuntu-latest, macOS-latest, windows-latest]
     steps:
-      - uses: actions/checkout@v5
-      - uses: dtolnay/rust-toolchain@stable
-      - run: rustup component add clippy
+      - uses: actions/checkout@v6
       - run: cargo clippy --all-targets -- -D warnings
 
   min_version:
@@ -57,11 +52,11 @@ jobs:
       matrix:
         os: [ubuntu-latest, macOS-latest, windows-latest]
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@v6
       - uses: dtolnay/rust-toolchain@stable
         with:
           toolchain: ${{ env.RUST_MIN_SRV }}
-      - run: cargo test
+      - run: cargo check
 
   coverage:
     name: Code Coverage
@@ -74,15 +69,15 @@ jobs:
           - { os: macos-latest   , features: macos }
           - { os: windows-latest , features: windows }
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
+    - name: emulate nightly toolchain
+      run: echo "RUSTC_BOOTSTRAP=1" >> "${GITHUB_ENV}"
     - name: Initialize workflow variables
       id: vars
       shell: bash
       run: |
         ## VARs setup
         outputs() { step_id="vars"; for var in "$@" ; do echo steps.${step_id}.outputs.${var}="${!var}"; echo "${var}=${!var}" >> $GITHUB_OUTPUT; done; }
-        # toolchain
-        TOOLCHAIN="nightly" ## default to "nightly" toolchain (required for certain required unstable compiler flags) ## !maint: refactor when stable channel has needed support
         # * specify gnu-type TOOLCHAIN for windows; `grcov` requires gnu-style code coverage data files
         case ${{ matrix.job.os }} in windows-*) TOOLCHAIN="$TOOLCHAIN-x86_64-pc-windows-gnu" ;; esac;
         # * use requested TOOLCHAIN if specified
@@ -94,13 +89,12 @@ jobs:
         outputs CODECOV_FLAGS
 
     - name: rust toolchain ~ install
-      uses: dtolnay/rust-toolchain@nightly
+      uses: dtolnay/rust-toolchain@nightly # this job is not reproducible...
       with:
         components: llvm-tools-preview
     - name: Test
       run: cargo test --no-fail-fast
       env:
-        CARGO_INCREMENTAL: "0"
         RUSTC_WRAPPER: ""
         RUSTFLAGS: "-Cinstrument-coverage -Zcoverage-options=branch -Ccodegen-units=1 -Copt-level=0 -Coverflow-checks=off -Zpanic_abort_tests -Cpanic=abort"
         RUSTDOCFLAGS: "-Cpanic=abort"
@@ -109,12 +103,12 @@ jobs:
       id: build_grcov
       shell: bash
       run: |
-        git clone https://github.com/mozilla/grcov.git ~/grcov/
+        git clone --depth=1 https://github.com/mozilla/grcov.git ~/grcov/
         cd ~/grcov
         # Hardcode the version of crossbeam-epoch. See
         # https://github.com/uutils/coreutils/issues/3680
         sed -i -e "s|tempfile =|crossbeam-epoch = \"=0.9.8\"\ntempfile =|" Cargo.toml
-        cargo install --path .
+        cargo install --path . --locked
         cd -
 # Uncomment when the upstream issue
 # https://github.com/mozilla/grcov/issues/849 is fixed
@@ -134,17 +128,19 @@ jobs:
         # display coverage files
         grcov . --binary-path="${COVERAGE_REPORT_DIR}" --output-type files --ignore build.rs --ignore "vendor/*" --ignore "/*" --ignore "[a-zA-Z]:/*" --excl-br-line "^\s*((debug_)?assert(_eq|_ne)?!|#\[derive\()" | sort --unique
         # generate coverage report
-        grcov . --binary-path="${COVERAGE_REPORT_DIR}" --output-type lcov --output-path "${COVERAGE_REPORT_FILE}" --branch --ignore build.rs --ignore "vendor/*" --ignore "/*" --ignore "[a-zA-Z]:/*" --excl-br-line "^\s*((debug_)?assert(_eq|_ne)?!|#\[derive\()"
+        grcov . --binary-path="${COVERAGE_REPORT_DIR}" --output-type lcov --output-path "${COVERAGE_REPORT_FILE}" --branch --ignore build.rs --ignore "vendor/*" --ignore "/*" --ignore "[a-zA-Z]:/*" --excl-br-line "^\s*((debug_)?assert(_eq|_ne)?!|#\[derive\()" --source-dir .
         echo "report=${COVERAGE_REPORT_FILE}" >> $GITHUB_OUTPUT
     - name: Upload coverage results (to Codecov.io)
-      uses: codecov/codecov-action@v5
+      uses: codecov/codecov-action@v7
       with:
         token: ${{ secrets.CODECOV_TOKEN }}
         files: ${{ steps.coverage.outputs.report }}
-        ## flags: IntegrationTests, UnitTests, ${{ steps.vars.outputs.CODECOV_FLAGS }}
         flags: ${{ steps.vars.outputs.CODECOV_FLAGS }}
         name: codecov-umbrella
         fail_ci_if_error: false
+        verbose: true
+        directory: ./
+        root_dir: ./
 
   fuzz:
     name: Run the fuzzers
@@ -152,14 +148,21 @@ jobs:
     env:
       RUN_FOR: 60
     steps:
-    - uses: actions/checkout@v5
-    - uses: dtolnay/rust-toolchain@nightly
+    - uses: actions/checkout@v6
+    - name: emulate nightly toolchain
+      run: echo "RUSTC_BOOTSTRAP=1" >> "${GITHUB_ENV}"
     - name: Install `cargo-fuzz`
-      run: cargo install cargo-fuzz
+      run: cargo install cargo-fuzz --locked
     - uses: Swatinem/rust-cache@v2
-    - name: Run from_str for XX seconds
+    - name: Run fuzz_parse_datetime for XX seconds
       shell: bash
       run: |
         ## Run it
         cd fuzz
-        cargo +nightly fuzz run fuzz_parse_datetime -- -max_total_time=${{ env.RUN_FOR }} -detect_leaks=0
+        cargo fuzz run fuzz_parse_datetime -- -max_total_time=${{ env.RUN_FOR }} -detect_leaks=0
+    - name: Run fuzz_large_year for XX seconds
+      shell: bash
+      run: |
+        ## Run it
+        cd fuzz
+        cargo fuzz run fuzz_large_year -- -max_total_time=${{ env.RUN_FOR }} -detect_leaks=0

.github/workflows/codspeed.yml

@@ -0,0 +1,37 @@
+name: CodSpeed
+
+on:
+  push:
+    branches:
+      - "main"
+  pull_request:
+  # `workflow_dispatch` allows CodSpeed to trigger backtest
+  # performance analysis in order to generate initial data.
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  id-token: write
+
+jobs:
+  codspeed:
+    name: Run benchmarks
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Setup rust toolchain, cache and cargo-codspeed binary
+        uses: moonrepo/setup-rust@v1
+        with:
+          channel: stable
+          cache-target: release
+          bins: cargo-codspeed
+
+      - name: Build the benchmark target(s)
+        run: cargo codspeed build
+
+      - name: Run the benchmarks
+        uses: CodSpeedHQ/action@v4
+        with:
+          mode: simulation
+          run: cargo codspeed run

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "parse_datetime"
-description = "parsing human-readable time strings and converting them to a DateTime"
-version = "0.12.0"
+description = "parsing human-readable time strings and converting them to a Zoned datetime"
+version = "0.15.0"
 edition = "2021"
 license = "MIT"
 repository = "https://github.com/uutils/parse_datetime"
@@ -9,10 +9,16 @@ readme = "README.md"
 rust-version = "1.71.1"
 
 [dependencies]
-regex = "1.10.4"
-winnow = "0.7.10"
+winnow = "1.0.0"
 num-traits = "0.2.19"
 jiff = { version = "0.2.15", default-features = false, features = ["tz-system", "tzdb-bundle-platform", "tzdb-zoneinfo"] }
 
 [dev-dependencies]
 rstest = "0.26"
+
+[dev-dependencies.codspeed-criterion-compat]
+version = "4.0"
+
+[[bench]]
+name = "parse_datetime"
+harness = false

README.md

@@ -3,8 +3,10 @@
 [![Crates.io](https://img.shields.io/crates/v/parse_datetime.svg)](https://crates.io/crates/parse_datetime)
 [![License](http://img.shields.io/badge/license-MIT-blue.svg)](https://github.com/uutils/parse_datetime/blob/main/LICENSE)
 [![CodeCov](https://codecov.io/gh/uutils/parse_datetime/branch/main/graph/badge.svg)](https://codecov.io/gh/uutils/parse_datetime)
+[![CodSpeed](https://img.shields.io/endpoint?url=https://codspeed.io/badge.json)](https://codspeed.io/uutils/parse_datetime?utm_source=badge)
 
-A Rust crate for parsing human-readable relative time strings and human-readable datetime strings and converting them to a jiff's `Zoned` object.
+A Rust crate for parsing human-readable relative time strings and
+human-readable datetime strings.
 
 ## Features
 
@@ -26,25 +28,44 @@ Then, import the crate and use the `parse_datetime_at_date` function:
 
 ```rs
 use jiff::{ToSpan, Zoned};
-use parse_datetime::parse_datetime_at_date;
+use parse_datetime::{parse_datetime_at_date, ParsedDateTime};
 
 let now = Zoned::now();
 let after = parse_datetime_at_date(now.clone(), "+3 days");
 
-assert_eq!(
-  now.checked_add(3.days()).unwrap(),
-  after.unwrap()
-);
+match after.unwrap() {
+  ParsedDateTime::InRange(z) => assert_eq!(now.checked_add(3.days()).unwrap(), z),
+  ParsedDateTime::Extended(_) => unreachable!("unexpected for this input"),
+}
 ```
 
 For DateTime parsing, import the `parse_datetime` function:
 
 ```rs
 use jiff::{civil::{date, time} ,Zoned};
-use parse_datetime::parse_datetime;
+use parse_datetime::{parse_datetime, ParsedDateTime};
 
 let dt = parse_datetime("2021-02-14 06:37:47");
-assert_eq!(dt.unwrap(), Zoned::now().with().date(date(2021, 2, 14)).time(time(6, 37, 47, 0)).build().unwrap());
+match dt.unwrap() {
+  ParsedDateTime::InRange(z) => assert_eq!(z, Zoned::now().with().date(date(2021, 2, 14)).time(time(6, 37, 47, 0)).build().unwrap()),
+  ParsedDateTime::Extended(_) => unreachable!("unexpected for this input"),
+}
+```
+
+For years beyond jiff's representable range (e.g., year 10000+), the result is an `ExtendedDateTime`:
+
+```rs
+use parse_datetime::{parse_datetime, ParsedDateTime};
+
+let dt = parse_datetime("12000-01-01").unwrap();
+match dt {
+  ParsedDateTime::Extended(ext) => {
+    assert_eq!(ext.year, 12000);
+    assert_eq!(ext.month, 1);
+    assert_eq!(ext.day, 1);
+  }
+  ParsedDateTime::InRange(_) => unreachable!("year 12000 is out of jiff range"),
+}
 ```
 
 ### Supported Formats
@@ -69,7 +90,9 @@ The `parse_datetime` and `parse_datetime_at_date` functions support absolute dat
 
 The `parse_datetime` and `parse_datetime_at_date` function return:
 
-- `Ok(Zoned)` - If the input string can be parsed as a `Zoned` object
+- `Ok(ParsedDateTime)` - If the input string can be parsed
+  - `ParsedDateTime::InRange(Zoned)` for years supported by `jiff::Zoned`
+  - `ParsedDateTime::Extended(ExtendedDateTime)` for out-of-range years (for example `>9999`)
 - `Err(ParseDateTimeError::InvalidInput)` - If the input string cannot be parsed
 
 ## Fuzzer

benches/parse_datetime.rs

@@ -0,0 +1,146 @@
+use codspeed_criterion_compat::{criterion_group, criterion_main, Criterion};
+use jiff::Zoned;
+use parse_datetime::{parse_datetime, parse_datetime_at_date};
+
+fn bench_iso_datetime(c: &mut Criterion) {
+    c.bench_function("parse_iso_datetime", |b| {
+        b.iter(|| parse_datetime("2021-02-14 06:37:47 +0000"))
+    });
+}
+
+fn bench_iso_datetime_t_sep(c: &mut Criterion) {
+    c.bench_function("parse_iso_datetime_t_separator", |b| {
+        b.iter(|| parse_datetime("2021-02-14T22:37:47-0800"))
+    });
+}
+
+fn bench_date_only(c: &mut Criterion) {
+    c.bench_function("parse_date_only", |b| {
+        b.iter(|| parse_datetime("1997-01-01"))
+    });
+}
+
+fn bench_date_slash_format(c: &mut Criterion) {
+    c.bench_function("parse_date_slash_format", |b| {
+        b.iter(|| parse_datetime("05/07/1987"))
+    });
+}
+
+fn bench_epoch_timestamp(c: &mut Criterion) {
+    c.bench_function("parse_epoch_timestamp", |b| {
+        b.iter(|| parse_datetime("@1613371067"))
+    });
+}
+
+fn bench_relative_time(c: &mut Criterion) {
+    let now = Zoned::now();
+    c.bench_function("parse_relative_time", |b| {
+        b.iter(|| parse_datetime_at_date(now.clone(), "+3 days"))
+    });
+}
+
+fn bench_relative_time_complex(c: &mut Criterion) {
+    let now = Zoned::now();
+    c.bench_function("parse_relative_time_complex", |b| {
+        b.iter(|| parse_datetime_at_date(now.clone(), "1 year 3 months 2 days ago"))
+    });
+}
+
+fn bench_relative_keywords(c: &mut Criterion) {
+    c.bench_function("parse_yesterday", |b| {
+        b.iter(|| parse_datetime("yesterday"))
+    });
+    c.bench_function("parse_tomorrow", |b| b.iter(|| parse_datetime("tomorrow")));
+    c.bench_function("parse_now", |b| b.iter(|| parse_datetime("now")));
+}
+
+fn bench_weekday(c: &mut Criterion) {
+    c.bench_function("parse_weekday", |b| b.iter(|| parse_datetime("wednesday")));
+}
+
+fn bench_timezone_offset(c: &mut Criterion) {
+    c.bench_function("parse_timezone_offset", |b| {
+        b.iter(|| parse_datetime("UTC+07:00"))
+    });
+}
+
+fn bench_datetime_with_delta(c: &mut Criterion) {
+    c.bench_function("parse_datetime_with_delta", |b| {
+        b.iter(|| parse_datetime("1997-01-01 00:00:00 +0000 +1 year"))
+    });
+}
+
+fn bench_ctime_format(c: &mut Criterion) {
+    c.bench_function("parse_ctime_format", |b| {
+        b.iter(|| parse_datetime("Wed Jan  1 00:00:00 1997"))
+    });
+}
+
+fn bench_datetime_with_timezone_name(c: &mut Criterion) {
+    c.bench_function("parse_datetime_with_tz_name", |b| {
+        b.iter(|| parse_datetime("1997-01-19 08:17:48 BRT"))
+    });
+}
+
+fn bench_datetime_ending_in_z(c: &mut Criterion) {
+    c.bench_function("parse_datetime_ending_in_z", |b| {
+        b.iter(|| parse_datetime("2023-06-03 12:00:01Z"))
+    });
+}
+
+fn bench_invalid_input(c: &mut Criterion) {
+    c.bench_function("parse_invalid_input", |b| {
+        b.iter(|| parse_datetime("NotADate"))
+    });
+}
+
+fn bench_extended_year(c: &mut Criterion) {
+    c.bench_function("parse_extended_year", |b| {
+        b.iter(|| parse_datetime("10000-01-01"))
+    });
+}
+
+fn bench_extended_year_rollover(c: &mut Criterion) {
+    c.bench_function("parse_extended_year_rollover", |b| {
+        b.iter(|| parse_datetime("9999-12-31 +1 day"))
+    });
+}
+
+fn bench_extended_year_relative(c: &mut Criterion) {
+    let base = jiff::civil::DateTime::from(jiff::civil::date(2000, 1, 1))
+        .to_zoned(jiff::tz::TimeZone::UTC)
+        .unwrap();
+    c.bench_function("parse_extended_year_relative", |b| {
+        b.iter(|| parse_datetime_at_date(base.clone(), "10000-01-01 +1 day"))
+    });
+}
+
+fn bench_extended_large_year(c: &mut Criterion) {
+    c.bench_function("parse_extended_large_year", |b| {
+        b.iter(|| parse_datetime("999999-06-15"))
+    });
+}
+
+criterion_group!(
+    benches,
+    bench_iso_datetime,
+    bench_iso_datetime_t_sep,
+    bench_date_only,
+    bench_date_slash_format,
+    bench_epoch_timestamp,
+    bench_relative_time,
+    bench_relative_time_complex,
+    bench_relative_keywords,
+    bench_weekday,
+    bench_timezone_offset,
+    bench_datetime_with_delta,
+    bench_ctime_format,
+    bench_datetime_with_timezone_name,
+    bench_datetime_ending_in_z,
+    bench_invalid_input,
+    bench_extended_year,
+    bench_extended_year_rollover,
+    bench_extended_year_relative,
+    bench_extended_large_year,
+);
+criterion_main!(benches);

fuzz/Cargo.lock

@@ -2,20 +2,14 @@
 # It is not intended for manual editing.
 version = 4
 
-[[package]]
-name = "aho-corasick"
-version = "1.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "arbitrary"
 version = "1.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c3d036a3c4ab069c7b410a2ce876bd74808d2d0888a82667669f8e783a898bf1"
+dependencies = [
+ "derive_arbitrary",
+]
 
 [[package]]
 name = "autocfg"
@@ -25,9 +19,9 @@ checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
 
 [[package]]
 name = "cc"
-version = "1.2.37"
+version = "1.2.58"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "65193589c6404eb80b450d618eaf9a2cafaaafd57ecce47370519ef674a7bd44"
+checksum = "e1e928d4b69e3077709075a938a05ffbedfa53a84c8f766efbf8220bb1ff60e1"
 dependencies = [
  "find-msvc-tools",
  "jobserver",
@@ -37,56 +31,69 @@ dependencies = [
 
 [[package]]
 name = "cfg-if"
-version = "1.0.3"
+version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2fd1289c04a9ea8cb22300a459a72a385d7c73d3259e2ed7dcb2af674838cfa9"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
+
+[[package]]
+name = "derive_arbitrary"
+version = "1.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1e567bd82dcff979e4b03460c307b3cdc9e96fde3d73bed1496d2bc75d9dd62a"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
 
 [[package]]
 name = "find-msvc-tools"
-version = "0.1.1"
+version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7fd99930f64d146689264c637b5af2f0233a933bef0d8570e2526bf9e083192d"
+checksum = "5baebc0774151f905a1a2cc41989300b1e6fbb29aff0ceffa1064fdd3088d582"
 
 [[package]]
 name = "fuzz_parse_datetime"
 version = "0.2.0"
 dependencies = [
+ "arbitrary",
+ "jiff",
  "libfuzzer-sys",
  "parse_datetime",
 ]
 
 [[package]]
 name = "getrandom"
-version = "0.3.3"
+version = "0.3.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "26145e563e54f2cadc477553f1ec5ee650b00862f0a58bcd12cbdc5f0ea2d2f4"
+checksum = "899def5c37c4fd7b2664648c28120ecec138e4d395b459e5ca34f9cce2dd77fd"
 dependencies = [
  "cfg-if",
  "libc",
  "r-efi",
- "wasi",
+ "wasip2",
 ]
 
 [[package]]
 name = "jiff"
-version = "0.2.15"
+version = "0.2.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "be1f93b8b1eb69c77f24bbb0afdf66f54b632ee39af40ca21c4365a1d7347e49"
+checksum = "4603d3033e49e2b0e31229fcab20a5d40089c607d975cd9c80551dc69eed9102"
 dependencies = [
  "jiff-static",
  "jiff-tzdb-platform",
  "log",
  "portable-atomic",
  "portable-atomic-util",
- "serde",
- "windows-sys",
+ "serde_core",
+ "windows-link",
 ]
 
 [[package]]
 name = "jiff-static"
-version = "0.2.15"
+version = "0.2.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "03343451ff899767262ec32146f6d559dd759fdadf42ff0e227c7c48f72594b4"
+checksum = "782d32378dddf207193ac91cefb848ad41abb58195c95168e1291227a0832b47"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -95,9 +102,9 @@ dependencies = [
 
 [[package]]
 name = "jiff-tzdb"
-version = "0.1.4"
+version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c1283705eb0a21404d2bfd6eef2a7593d240bc42a0bdb39db0ad6fa2ec026524"
+checksum = "c900ef84826f1338a557697dc8fc601df9ca9af4ac137c7fb61d4c6f2dfd3076"
 
 [[package]]
 name = "jiff-tzdb-platform"
@@ -120,15 +127,15 @@ dependencies = [
 
 [[package]]
 name = "libc"
-version = "0.2.175"
+version = "0.2.183"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a82ae493e598baaea5209805c49bbf2ea7de956d50d7da0da1164f9c6d28543"
+checksum = "b5b646652bf6661599e1da8901b3b9522896f01e736bad5f723fe7a3a27f899d"
 
 [[package]]
 name = "libfuzzer-sys"
-version = "0.4.10"
+version = "0.4.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5037190e1f70cbeef565bd267599242926f724d3b8a9f510fd7e0b540cfa4404"
+checksum = "a9fd2f41a1cba099f79a0b6b6c35656cf7c03351a7bae8ff0f28f25270f929d2"
 dependencies = [
  "arbitrary",
  "cc",
@@ -136,15 +143,15 @@ dependencies = [
 
 [[package]]
 name = "log"
-version = "0.4.28"
+version = "0.4.29"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "34080505efa8e45a4b816c349525ebe327ceaa8559756f0356cba97ef3bf7432"
+checksum = "5e5032e24019045c762d3c0f28f5b6b8bbf38563a65908389bf7978758920897"
 
 [[package]]
 name = "memchr"
-version = "2.7.5"
+version = "2.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32a282da65faaf38286cf3be983213fcf1d2e2a58700e808f83f4ea9a4804bc0"
+checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
 
 [[package]]
 name = "num-traits"
@@ -157,43 +164,42 @@ dependencies = [
 
 [[package]]
 name = "parse_datetime"
-version = "0.11.0"
+version = "0.15.0"
 dependencies = [
  "jiff",
  "num-traits",
- "regex",
  "winnow",
 ]
 
 [[package]]
 name = "portable-atomic"
-version = "1.11.1"
+version = "1.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f84267b20a16ea918e43c6a88433c2d54fa145c92a811b5b047ccbe153674483"
+checksum = "c33a9471896f1c69cecef8d20cbe2f7accd12527ce60845ff44c153bb2a21b49"
 
 [[package]]
 name = "portable-atomic-util"
-version = "0.2.4"
+version = "0.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d8a2f0d8d040d7848a709caf78912debcc3f33ee4b3cac47d73d1e1069e83507"
+checksum = "091397be61a01d4be58e7841595bd4bfedb15f1cd54977d79b8271e94ed799a3"
 dependencies = [
  "portable-atomic",
 ]
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.101"
+version = "1.0.106"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "89ae43fd86e4158d6db51ad8e2b80f313af9cc74f5c0e03ccb87de09998732de"
+checksum = "8fd00f0bb2e90d81d1044c2b32617f68fcb9fa3bb7640c23e9c748e53fb30934"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.40"
+version = "1.0.45"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1885c039570dc00dcb4ff087a89e185fd56bae234ddc7f056a945bf36467248d"
+checksum = "41f2619966050689382d2b44f664f4bc593e129785a36d6ee376ddf37259b924"
 dependencies = [
  "proc-macro2",
 ]
@@ -204,58 +210,20 @@ version = "5.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "69cdb34c158ceb288df11e18b4bd39de994f6657d83847bdffdbd7f346754b0f"
 
-[[package]]
-name = "regex"
-version = "1.11.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "23d7fd106d8c02486a8d64e778353d1cffe08ce79ac2e82f540c86d0facf6912"
-dependencies = [
- "aho-corasick",
- "memchr",
- "regex-automata",
- "regex-syntax",
-]
-
-[[package]]
-name = "regex-automata"
-version = "0.4.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6b9458fa0bfeeac22b5ca447c63aaf45f28439a709ccd244698632f9aa6394d6"
-dependencies = [
- "aho-corasick",
- "memchr",
- "regex-syntax",
-]
-
-[[package]]
-name = "regex-syntax"
-version = "0.8.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "caf4aa5b0f434c91fe5c7f1ecb6a5ece2130b02ad2a590589dda5146df959001"
-
-[[package]]
-name = "serde"
-version = "1.0.221"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "341877e04a22458705eb4e131a1508483c877dca2792b3781d4e5d8a6019ec43"
-dependencies = [
- "serde_core",
-]
-
 [[package]]
 name = "serde_core"
-version = "1.0.221"
+version = "1.0.228"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0c459bc0a14c840cb403fc14b148620de1e0778c96ecd6e0c8c3cacb6d8d00fe"
+checksum = "41d385c7d4ca58e59fc732af25c3983b67ac852c1a25000afe1175de458b67ad"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.221"
+version = "1.0.228"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d6185cf75117e20e62b1ff867b9518577271e58abe0037c40bb4794969355ab0"
+checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -270,9 +238,9 @@ checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
 
 [[package]]
 name = "syn"
-version = "2.0.106"
+version = "2.0.117"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ede7c438028d4436d71104916910f5bb611972c5cfd7f89b8300a8186e6fada6"
+checksum = "e665b8803e7b1d2a727f4023456bbbbe74da67099c585258af0ad9c5013b9b99"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -281,112 +249,36 @@ dependencies = [
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.19"
+version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f63a545481291138910575129486daeaf8ac54aee4387fe7906919f7830c7d9d"
-
-[[package]]
-name = "wasi"
-version = "0.14.5+wasi-0.2.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4494f6290a82f5fe584817a676a34b9d6763e8d9d18204009fb31dceca98fd4"
-dependencies = [
- "wasip2",
-]
+checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 
 [[package]]
 name = "wasip2"
-version = "1.0.0+wasi-0.2.4"
+version = "1.0.2+wasi-0.2.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "03fa2761397e5bd52002cd7e73110c71af2109aca4e521a9f40473fe685b0a24"
+checksum = "9517f9239f02c069db75e65f174b3da828fe5f5b945c4dd26bd25d89c03ebcf5"
 dependencies = [
  "wit-bindgen",
 ]
 
 [[package]]
-name = "windows-sys"
-version = "0.59.0"
+name = "windows-link"
+version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
-dependencies = [
- "windows-targets",
-]
-
-[[package]]
-name = "windows-targets"
-version = "0.52.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
-dependencies = [
- "windows_aarch64_gnullvm",
- "windows_aarch64_msvc",
- "windows_i686_gnu",
- "windows_i686_gnullvm",
- "windows_i686_msvc",
- "windows_x86_64_gnu",
- "windows_x86_64_gnullvm",
- "windows_x86_64_msvc",
-]
-
-[[package]]
-name = "windows_aarch64_gnullvm"
-version = "0.52.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
-
-[[package]]
-name = "windows_aarch64_msvc"
-version = "0.52.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
-
-[[package]]
-name = "windows_i686_gnu"
-version = "0.52.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
-
-[[package]]
-name = "windows_i686_gnullvm"
-version = "0.52.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
-
-[[package]]
-name = "windows_i686_msvc"
-version = "0.52.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
-
-[[package]]
-name = "windows_x86_64_gnu"
-version = "0.52.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
-
-[[package]]
-name = "windows_x86_64_gnullvm"
-version = "0.52.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
-
-[[package]]
-name = "windows_x86_64_msvc"
-version = "0.52.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
+checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
 
 [[package]]
 name = "winnow"
-version = "0.7.13"
+version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "21a0236b59786fed61e2a80582dd500fe61f18b5dca67a4a067d0bc9039339cf"
+checksum = "2ee1708bef14716a11bae175f579062d4554d95be2c6829f518df847b7b3fdd0"
 dependencies = [
  "memchr",
 ]
 
 [[package]]
 name = "wit-bindgen"
-version = "0.45.1"
+version = "0.51.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5c573471f125075647d03df72e026074b7203790d41351cd6edc96f46bcccd36"
+checksum = "d7249219f66ced02969388cf2bb044a09756a083d0fab1e566056b04d9fbcaa5"

fuzz/Cargo.toml

@@ -8,6 +8,8 @@ cargo-fuzz = true
 
 [dependencies]
 libfuzzer-sys = "0.4.7"
+arbitrary = { version = "1", features = ["derive"] }
+jiff = "0.2"
 
 [dependencies.parse_datetime]
 path = "../"
@@ -17,3 +19,9 @@ name = "fuzz_parse_datetime"
 path = "fuzz_targets/parse_datetime.rs"
 test = false
 doc = false
+
+[[bin]]
+name = "fuzz_large_year"
+path = "fuzz_targets/large_year.rs"
+test = false
+doc = false

fuzz/fuzz_targets/large_year.rs

@@ -0,0 +1,64 @@
+#![no_main]
+
+use arbitrary::Arbitrary;
+use jiff::{civil::DateTime, tz::TimeZone};
+use libfuzzer_sys::fuzz_target;
+
+#[derive(Arbitrary, Debug)]
+struct Input {
+    /// Year for the base date (biased toward boundary years).
+    base_year_selector: u8,
+    /// Year to embed in a constructed large-year input string.
+    input_year: u32,
+    month: u8,
+    day: u8,
+    /// Suffix appended after the constructed date (e.g. relative items).
+    suffix: String,
+    /// Whether to also call parse_datetime (no base).
+    try_no_base: bool,
+}
+
+fn base_year(selector: u8) -> i16 {
+    match selector % 6 {
+        0 => 2024,
+        1 => 9998,
+        2 => 9999,
+        3 => 1,
+        4 => 100,
+        _ => (selector as i16) * 40,
+    }
+}
+
+fn clamp_year(y: u32) -> u32 {
+    // Focus on the interesting range: 9990..=100_000 and 0..=20_000
+    match y % 4 {
+        0 => 9990 + (y % 20),          // near boundary
+        1 => 10000 + (y % 90_000),     // large years
+        2 => y % 20_000,               // general range
+        _ => 2_147_485_540 + (y % 10), // near GNU_MAX_YEAR
+    }
+}
+
+fuzz_target!(|input: Input| {
+    let year = clamp_year(input.input_year);
+    let month = (input.month % 12) + 1;
+    let day = (input.day % 28) + 1;
+    let date_str = format!("{year:04}-{month:02}-{day:02} {}", input.suffix);
+
+    // Test parse_datetime (uses current time as base).
+    if input.try_no_base {
+        let _ = parse_datetime::parse_datetime(&date_str);
+    }
+
+    // Test parse_datetime_at_date with a controlled base.
+    let by = base_year(input.base_year_selector);
+    if let Ok(base) = DateTime::new(by, 1, 1, 0, 0, 0, 0) {
+        if let Ok(base) = base.to_zoned(TimeZone::UTC) {
+            let _ = parse_datetime::parse_datetime_at_date(base, &date_str);
+        }
+    }
+
+    // Also try a bare large year as a pure number.
+    let bare = format!("{year}");
+    let _ = parse_datetime::parse_datetime(&bare);
+});

src/items/date.rs

@@ -44,11 +44,11 @@ use super::{
 pub(crate) struct Date {
     pub(crate) day: u8,
     pub(crate) month: u8,
-    pub(crate) year: Option<u16>,
+    pub(crate) year: Option<u32>,
 }
 
 impl Date {
-    pub(super) fn with_year(self, year: u16) -> Self {
+    pub(super) fn with_year(self, year: u32) -> Self {
         Date {
             day: self.day,
             month: self.month,
@@ -118,17 +118,17 @@ impl TryFrom<Date> for jiff::civil::Date {
     type Error = &'static str;
 
     fn try_from(date: Date) -> Result<Self, Self::Error> {
-        jiff::civil::Date::new(
-            date.year.unwrap_or(0) as i16,
-            date.month as i8,
-            date.day as i8,
-        )
-        .map_err(|_| "date is not valid")
+        let year = date.year.unwrap_or(0);
+        let year: i16 = year
+            .try_into()
+            .map_err(|_| "date year is outside the supported range")?;
+        jiff::civil::Date::new(year, date.month as i8, date.day as i8)
+            .map_err(|_| "date is not valid")
     }
 }
 
 pub(super) fn parse(input: &mut &str) -> ModalResult<Date> {
-    alt((iso1, iso2, us, literal1, literal2)).parse_next(input)
+    alt((iso1, iso2, us, literal1, literal2, literal3)).parse_next(input)
 }
 
 /// Parse `[year]-[month]-[day]`
@@ -138,9 +138,10 @@ pub(super) fn iso1(input: &mut &str) -> ModalResult<Date> {
     let (year, _, month, _, day) =
         (year_str, s('-'), s(dec_uint), s('-'), s(dec_uint)).parse_next(input)?;
 
+    // Map err to Backtrack instead of Cut to avoid early termination of parsing
     (year, month, day)
         .try_into()
-        .map_err(|e| ErrMode::Cut(ctx_err(e)))
+        .map_err(|e| ErrMode::Backtrack(ctx_err(e)))
 }
 
 /// Parse `[year][month][day]`
@@ -156,7 +157,7 @@ pub(super) fn iso2(input: &mut &str) -> ModalResult<Date> {
 
     (year, month, day)
         .try_into()
-        .map_err(|e| ErrMode::Cut(ctx_err(e)))
+        .map_err(|e| ErrMode::Backtrack(ctx_err(e)))
 }
 
 /// Parse `[year]/[month]/[day]` or `[month]/[day]/[year]` or `[month]/[day]`.
@@ -178,19 +179,21 @@ fn us(input: &mut &str) -> ModalResult<Date> {
             let day = day_from_str(s2)?;
             (s1, n, day)
                 .try_into()
-                .map_err(|e| ErrMode::Cut(ctx_err(e)))
+                .map_err(|e| ErrMode::Backtrack(ctx_err(e)))
         }
         Some(s2) => {
             // [month]/[day]/[year]
             let month = month_from_str(s1)?;
             (s2, month, n)
                 .try_into()
-                .map_err(|e| ErrMode::Cut(ctx_err(e)))
+                .map_err(|e| ErrMode::Backtrack(ctx_err(e)))
         }
         None => {
             // [month]/[day]
             let month = month_from_str(s1)?;
-            (month, n).try_into().map_err(|e| ErrMode::Cut(ctx_err(e)))
+            (month, n)
+                .try_into()
+                .map_err(|e| ErrMode::Backtrack(ctx_err(e)))
         }
     }
 }
@@ -213,10 +216,10 @@ fn literal1(input: &mut &str) -> ModalResult<Date> {
     match year {
         Some(year) => (year, month, day)
             .try_into()
-            .map_err(|e| ErrMode::Cut(ctx_err(e))),
+            .map_err(|e| ErrMode::Backtrack(ctx_err(e))),
         None => (month, day)
             .try_into()
-            .map_err(|e| ErrMode::Cut(ctx_err(e))),
+            .map_err(|e| ErrMode::Backtrack(ctx_err(e))),
     }
 }
 
@@ -242,13 +245,25 @@ fn literal2(input: &mut &str) -> ModalResult<Date> {
     match year {
         Some(year) => (year, month, day)
             .try_into()
-            .map_err(|e| ErrMode::Cut(ctx_err(e))),
+            .map_err(|e| ErrMode::Backtrack(ctx_err(e))),
         None => (month, day)
             .try_into()
-            .map_err(|e| ErrMode::Cut(ctx_err(e))),
+            .map_err(|e| ErrMode::Backtrack(ctx_err(e))),
     }
 }
 
+/// Parse `November-14-2022` and `Nov-14-2022`. Unlike `literal2`, the year is mandatory
+/// to match the behavior of GNU `date`.
+fn literal3(input: &mut &str) -> ModalResult<Date> {
+    let (month, _, day, _, year) =
+        (s(literal_month), s('-'), s(dec_uint), s('-'), year_str).parse_next(input)?;
+
+    // Map err to Backtrack instead of Cut to avoid early termination of parsing
+    (year, month, day)
+        .try_into()
+        .map_err(|e| ErrMode::Backtrack(ctx_err(e)))
+}
+
 /// Parse the name of a month (case-insensitive)
 fn literal_month(input: &mut &str) -> ModalResult<u8> {
     s(alpha1)
@@ -274,12 +289,12 @@ fn literal_month(input: &mut &str) -> ModalResult<u8> {
 
 fn month_from_str(s: &str) -> ModalResult<u8> {
     s.parse::<u8>()
-        .map_err(|_| ErrMode::Cut(ctx_err("month must be a valid u8 number")))
+        .map_err(|_| ErrMode::Backtrack(ctx_err("month must be a valid u8 number")))
 }
 
 fn day_from_str(s: &str) -> ModalResult<u8> {
     s.parse::<u8>()
-        .map_err(|_| ErrMode::Cut(ctx_err("day must be a valid u8 number")))
+        .map_err(|_| ErrMode::Backtrack(ctx_err("day must be a valid u8 number")))
 }
 
 #[cfg(test)]
@@ -546,6 +561,27 @@ mod tests {
         assert_eq!(s, ", 2022a");
     }
 
+    #[test]
+    fn literal3() {
+        let reference = Date {
+            year: Some(2022),
+            month: 11,
+            day: 14,
+        };
+
+        for mut s in [
+            "november-14-2022",
+            "november----14----2022",
+            "november  -  14   -  2022",
+            "nov-14-2022",
+            "nov---14---2022",
+            "nov  -   14    -   2022",
+        ] {
+            let old_s = s.to_owned();
+            assert_eq!(parse(&mut s).unwrap(), reference, "Format string: {old_s}");
+        }
+    }
+
     #[test]
     fn with_year() {
         let reference = Date {

src/items/epoch.rs

@@ -33,7 +33,7 @@ use super::primitive::{dec_uint, plus_or_minus, s};
 /// - `nanosecond` is always in the range of `0..1_000_000_000`.
 /// - Negative timestamps are represented by a negative `second` value and a
 ///   positive `nanosecond` value.
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Clone, Copy)]
 pub(super) struct Timestamp {
     second: i64,
     nanosecond: u32,

src/items/mod.rs

@@ -21,6 +21,7 @@
 //!  - [`combined`]
 //!  - [`date`]
 //!  - [`epoch`]
+//!  - [`offset`]
 //!  - [`pure`]
 //!  - [`relative`]
 //!  - [`time`]
@@ -32,6 +33,7 @@
 mod combined;
 mod date;
 mod epoch;
+mod offset;
 mod pure;
 mod relative;
 mod time;
@@ -46,6 +48,7 @@ mod primitive;
 
 pub(crate) mod error;
 
+use crate::ParsedDateTime;
 use jiff::Zoned;
 use primitive::space;
 use winnow::{
@@ -60,31 +63,32 @@ use error::Error;
 
 #[derive(PartialEq, Debug)]
 enum Item {
-    Timestamp(epoch::Timestamp),
     DateTime(combined::DateTime),
     Date(date::Date),
     Time(time::Time),
     Weekday(weekday::Weekday),
     Relative(relative::Relative),
-    TimeZone(timezone::Offset),
+    Offset(offset::Offset),
+    TimeZone(jiff::tz::TimeZone),
     Pure(String),
 }
 
-/// Parse a date and time string and build a `Zoned` object. The parsed result
-/// is resolved against the given base date and time.
-pub(crate) fn parse_at_date<S: AsRef<str> + Clone>(base: Zoned, input: S) -> Result<Zoned, Error> {
-    let input = input.as_ref().to_ascii_lowercase();
-    match parse(&mut input.as_str()) {
+/// Parse a date and time string and resolve it against the given base date and
+/// time, returning a [`ParsedDateTime`] result.
+pub(crate) fn parse_at_date<S: AsRef<str> + Clone>(
+    base: Zoned,
+    input: S,
+) -> Result<ParsedDateTime, Error> {
+    match parse(&mut input.as_ref()) {
         Ok(builder) => builder.set_base(base).build(),
         Err(e) => Err(e.into()),
     }
 }
 
-/// Parse a date and time string and build a `Zoned` object. The parsed result
-/// is resolved against the current local date and time.
-pub(crate) fn parse_at_local<S: AsRef<str> + Clone>(input: S) -> Result<Zoned, Error> {
-    let input = input.as_ref().to_ascii_lowercase();
-    match parse(&mut input.as_str()) {
+/// Parse a date and time string and resolve it against the current local date
+/// and time, returning a [`ParsedDateTime`] result.
+pub(crate) fn parse_at_local<S: AsRef<str> + Clone>(input: S) -> Result<ParsedDateTime, Error> {
+    match parse(&mut input.as_ref()) {
         Ok(builder) => builder.build(), // the builder uses current local date and time if no base is given.
         Err(e) => Err(e.into()),
     }
@@ -95,12 +99,14 @@ pub(crate) fn parse_at_local<S: AsRef<str> + Clone>(input: S) -> Result<Zoned, E
 /// Grammar:
 ///
 /// ```ebnf
-/// spec                = timestamp | items ;
+/// spec                = [ tz_rule ] ( timestamp | items ) ;
+///
+/// tz_rule            = "TZ=" , "\"" , ( posix_tz | iana_tz ) , "\"" ;
 ///
 /// timestamp           = "@" , float ;
 ///
 /// items               = item , { item } ;
-/// item                = datetime | date | time | relative | weekday | timezone | pure ;
+/// item                = datetime | date | time | relative | weekday | offset | pure ;
 ///
 /// datetime            = date , [ "t" | whitespace ] , iso_time ;
 ///
@@ -179,7 +185,7 @@ pub(crate) fn parse_at_local<S: AsRef<str> + Clone>(input: S) -> Result<Zoned, E
 ///                     | "saturday" | "sat" | "sat."
 ///                     | "sunday" | "sun" | "sun." ;
 ///
-/// timezone            = named_zone , [ time_offset ] ;
+/// offset             = named_zone , [ time_offset ] ;
 ///
 /// pure               = { digit }
 ///
@@ -189,35 +195,57 @@ fn parse(input: &mut &str) -> ModalResult<DateTimeBuilder> {
     trace("parse", alt((parse_timestamp, parse_items))).parse_next(input)
 }
 
-/// Parse a timestamp.
+/// Parse a standalone epoch timestamp (e.g., `@1758724019`).
 ///
-/// From the GNU docs:
+/// GNU `date` specifies that a timestamp item is *complete* and *must not* be
+/// combined with any other date/time item.
 ///
-/// > (Timestamp) Such a number cannot be combined with any other date item, as
-/// > it specifies a complete timestamp.
+/// Notes:
+///
+/// - If a timezone rule (`TZ="..."`) appears at the beginning of the input, it
+///   has no effect on the epoch value. We intentionally parse and ignore it.
+/// - Trailing input (aside from optional whitespaces) is rejected.
 fn parse_timestamp(input: &mut &str) -> ModalResult<DateTimeBuilder> {
+    // Parse and ignore an optional leading timezone rule.
+    let _ = timezone::parse(input);
+
     trace(
         "parse_timestamp",
-        terminated(epoch::parse.map(Item::Timestamp), preceded(space, eof)),
+        // Expect exactly one timestamp and then EOF (allowing trailing spaces).
+        terminated(epoch::parse, preceded(space, eof)),
     )
-    .verify_map(|ts: Item| {
-        if let Item::Timestamp(ts) = ts {
-            DateTimeBuilder::new().set_timestamp(ts).ok()
-        } else {
-            None
-        }
-    })
+    .verify_map(|ts| DateTimeBuilder::new().set_timestamp(ts).ok())
     .parse_next(input)
 }
 
-/// Parse a sequence of items.
+/// Parse a sequence of date/time items, honoring an optional leading TZ rule.
+///
+/// Notes:
+///
+/// - If a timezone rule (`TZ="..."`) appears at the beginning of the input,
+///   parse it first. The timezone rule is case-sensitive.
+/// - After the optional timezone rule is parsed, we convert the input to
+///   lowercase to allow case-insensitive parsing of the remaining items.
+/// - Trailing input (aside from optional whitespaces) is rejected.
 fn parse_items(input: &mut &str) -> ModalResult<DateTimeBuilder> {
-    let (items, _): (Vec<Item>, _) = trace(
+    // Parse and consume an optional leading timezone rule.
+    let tz = timezone::parse(input).map(Item::TimeZone);
+
+    // Convert input to lowercase for case-insensitive parsing.
+    let lower = input.to_ascii_lowercase();
+    let input = &mut lower.as_str();
+
+    let (mut items, _): (Vec<Item>, _) = trace(
         "parse_items",
+        // Parse zero or more items until EOF (allowing trailing spaces).
         repeat_till(0.., parse_item, preceded(space, eof)),
     )
     .parse_next(input)?;
 
+    if let Ok(tz) = tz {
+        items.push(tz);
+    }
+
     items.try_into().map_err(|e| expect_error(input, e))
 }
 
@@ -231,7 +259,7 @@ fn parse_item(input: &mut &str) -> ModalResult<Item> {
             time::parse.map(Item::Time),
             relative::parse.map(Item::Relative),
             weekday::parse.map(Item::Weekday),
-            timezone::parse.map(Item::TimeZone),
+            offset::parse.map(Item::Offset),
             pure::parse.map(Item::Pure),
         )),
     )
@@ -249,12 +277,13 @@ fn expect_error(input: &mut &str, reason: &'static str) -> ErrMode<ContextError>
 
 #[cfg(test)]
 mod tests {
+    use crate::ParsedDateTime;
     use jiff::{civil::DateTime, tz::TimeZone, ToSpan, Zoned};
 
-    use super::{parse, DateTimeBuilder};
+    use super::*;
 
     fn at_date(builder: DateTimeBuilder, base: Zoned) -> Zoned {
-        builder.set_base(base).build().unwrap()
+        builder.set_base(base).build().unwrap().expect_in_range()
     }
 
     fn at_utc(builder: DateTimeBuilder) -> Zoned {
@@ -271,6 +300,22 @@ mod tests {
             .to_string()
     }
 
+    fn assert_extended_datetime(input: &str, base: Zoned, expected: &str) {
+        let parsed = parse_at_date(base, input).unwrap();
+        assert!(
+            matches!(parsed, ParsedDateTime::Extended(_)),
+            "expected extended datetime, got in-range for: {input}"
+        );
+        assert_eq!(parsed.to_string(), expected, "{input}");
+    }
+
+    fn expect_extended_datetime(parsed: ParsedDateTime) -> crate::ExtendedDateTime {
+        match parsed {
+            ParsedDateTime::Extended(dt) => dt,
+            ParsedDateTime::InRange(z) => panic!("expected extended datetime, got in-range: {z}"),
+        }
+    }
+
     #[test]
     fn date_and_time() {
         assert_eq!(
@@ -369,7 +414,7 @@ mod tests {
         assert!(result
             .unwrap_err()
             .to_string()
-            .contains("timezone cannot appear more than once"));
+            .contains("time offset cannot appear more than once"));
 
         let result = parse(&mut "2025-05-19 abcdef");
         assert!(result.is_err());
@@ -380,13 +425,12 @@ mod tests {
         let result = parse(&mut "2025-05-19 @1690466034");
         assert!(result.is_err());
 
-        // Pure number as year (too large).
+        // Pure number as year (large years are accepted).
         let result = parse(&mut "jul 18 12:30 10000");
-        assert!(result.is_err());
-        assert!(result
-            .unwrap_err()
-            .to_string()
-            .contains("year must be no greater than 9999"));
+        assert!(result.is_ok());
+        let built = result.unwrap().build().unwrap();
+        let dt = expect_extended_datetime(built);
+        assert_eq!(dt.year, 10000);
 
         // Pure number as time (too long).
         let result = parse(&mut "01:02 12345");
@@ -421,6 +465,184 @@ mod tests {
             .contains("invalid minute in pure number"));
     }
 
+    #[test]
+    fn negative_base_year_with_yearless_date_errors() {
+        let base = DateTime::new(-1, 1, 1, 0, 0, 0, 0)
+            .unwrap()
+            .to_zoned(TimeZone::UTC)
+            .unwrap();
+        let result = parse_at_date(base, "11/14");
+        assert!(result.is_err());
+        assert!(result
+            .unwrap_err()
+            .to_string()
+            .contains("base year must be non-negative"));
+    }
+
+    #[test]
+    fn boundary_rollover_from_9999_falls_back_to_extended() {
+        let base = "2000-01-01 00:00:00"
+            .parse::<DateTime>()
+            .unwrap()
+            .to_zoned(TimeZone::UTC)
+            .unwrap();
+        assert_extended_datetime("9999-12-31 +1 day", base, "10000-01-01 00:00:00+00:00");
+    }
+
+    #[test]
+    fn boundary_year_9999_absolute_date_parses() {
+        let base = "2000-01-01 00:00:00"
+            .parse::<DateTime>()
+            .unwrap()
+            .to_zoned(TimeZone::UTC)
+            .unwrap();
+        assert_extended_datetime("9999-12-31", base, "9999-12-31 00:00:00+00:00");
+    }
+
+    #[test]
+    fn boundary_year_9999_with_time_parses() {
+        let base = "2000-01-01 00:00:00"
+            .parse::<DateTime>()
+            .unwrap()
+            .to_zoned(TimeZone::UTC)
+            .unwrap();
+        assert_extended_datetime("9999-12-31 12:00", base, "9999-12-31 12:00:00+00:00");
+    }
+
+    #[test]
+    fn boundary_year_9999_with_utc_timezone_parses() {
+        let base = "2000-01-01 00:00:00"
+            .parse::<DateTime>()
+            .unwrap()
+            .to_zoned(TimeZone::UTC)
+            .unwrap();
+        assert_extended_datetime("9999-12-31 12:00 UTC", base, "9999-12-31 12:00:00+00:00");
+    }
+
+    #[test]
+    fn boundary_year_9999_with_explicit_offset_parses() {
+        let base = "2000-01-01 00:00:00"
+            .parse::<DateTime>()
+            .unwrap()
+            .to_zoned(TimeZone::UTC)
+            .unwrap();
+        assert_extended_datetime("9999-12-31 12:00 +01:00", base, "9999-12-31 12:00:00+01:00");
+    }
+
+    #[test]
+    fn large_year_relative_parity_months_and_years() {
+        let base = "2000-01-01 00:00:00"
+            .parse::<DateTime>()
+            .unwrap()
+            .to_zoned(TimeZone::UTC)
+            .unwrap();
+
+        assert_extended_datetime(
+            "10000-01-31 +2 months",
+            base.clone(),
+            "10000-03-31 00:00:00+00:00",
+        );
+        assert_extended_datetime(
+            "10000-01-31 +3 months",
+            base.clone(),
+            "10000-05-01 00:00:00+00:00",
+        );
+        assert_extended_datetime(
+            "10000-08-31 +6 months",
+            base.clone(),
+            "10001-03-03 00:00:00+00:00",
+        );
+        assert_extended_datetime(
+            "10000-05-31 3 months ago",
+            base.clone(),
+            "10000-03-02 00:00:00+00:00",
+        );
+        assert_extended_datetime("10000-02-29 +1 year", base, "10001-03-01 00:00:00+00:00");
+    }
+
+    #[test]
+    fn rejects_year_above_gnu_max() {
+        assert!(parse_at_local("2147485548-01-01").is_err());
+    }
+
+    #[test]
+    fn large_year_can_return_in_range_after_relative() {
+        let base = "2000-01-01 00:00:00"
+            .parse::<DateTime>()
+            .unwrap()
+            .to_zoned(TimeZone::UTC)
+            .unwrap();
+        let result = parse_at_date(base, "10000-01-01 -1000 years").unwrap();
+        let z = result.expect_in_range();
+        assert_eq!(
+            z.strftime("%Y-%m-%d %H:%M:%S%:z").to_string(),
+            "9000-01-01 00:00:00+00:00"
+        );
+    }
+
+    #[test]
+    fn large_year_can_return_in_range_after_relative_with_named_timezone_rule() {
+        let base = "2000-01-01 00:00:00"
+            .parse::<DateTime>()
+            .unwrap()
+            .to_zoned(TimeZone::UTC)
+            .unwrap();
+        let result = parse_at_date(base, "TZ=\"Europe/Paris\" 10000-01-01 -1000 years").unwrap();
+        let z = result.expect_in_range();
+        assert_eq!(
+            z.strftime("%Y-%m-%d %H:%M:%S%:z").to_string(),
+            "9000-01-01 00:00:00+01:00"
+        );
+    }
+
+    #[test]
+    fn large_year_time_with_explicit_offset_is_extended() {
+        let base = "2000-01-01 00:00:00"
+            .parse::<DateTime>()
+            .unwrap()
+            .to_zoned(TimeZone::UTC)
+            .unwrap();
+        let dt =
+            expect_extended_datetime(parse_at_date(base, "10000-01-01 12:34:56+02:00").unwrap());
+        assert_eq!((dt.year, dt.month, dt.day), (10000, 1, 1));
+        assert_eq!((dt.hour, dt.minute, dt.second), (12, 34, 56));
+        assert_eq!(dt.offset_seconds, 2 * 3600);
+    }
+
+    #[test]
+    fn parse_at_date_returns_error_for_invalid_input() {
+        let base = "2000-01-01 00:00:00"
+            .parse::<DateTime>()
+            .unwrap()
+            .to_zoned(TimeZone::UTC)
+            .unwrap();
+        let result = parse_at_date(base, "not-a-date");
+        assert!(result.is_err());
+    }
+
+    #[test]
+    #[should_panic(expected = "expected extended datetime")]
+    fn assert_extended_datetime_panics_for_in_range_input() {
+        let base = "2000-01-01 00:00:00"
+            .parse::<DateTime>()
+            .unwrap()
+            .to_zoned(TimeZone::UTC)
+            .unwrap();
+        assert_extended_datetime("2001-01-01", base, "2001-01-01 00:00:00+00:00");
+    }
+
+    #[test]
+    #[should_panic(expected = "ParsedDateTime is not representable as jiff::Zoned")]
+    fn expect_in_range_panics_for_extended_input() {
+        let base = "2000-01-01 00:00:00"
+            .parse::<DateTime>()
+            .unwrap()
+            .to_zoned(TimeZone::UTC)
+            .unwrap();
+        let parsed = parse_at_date(base, "10000-01-01").unwrap();
+        let _ = parsed.expect_in_range();
+    }
+
     #[test]
     fn relative_weekday() {
         // Jan 1 2025 is a Wed
@@ -527,4 +749,26 @@ mod tests {
         assert_eq!(result.hour(), 1);
         assert_eq!(result.minute(), 0);
     }
+
+    #[test]
+    fn timezone_rule() {
+        let parse_build = |mut s| parse(&mut s).unwrap().build().unwrap();
+
+        for (input, expected) in [
+            (
+                r#"TZ="Europe/Paris" 2025-01-02"#,
+                "2025-01-02 00:00:00[Europe/Paris]"
+                    .parse::<Zoned>()
+                    .unwrap(),
+            ),
+            (
+                r#"TZ="Europe/Paris" 2025-01-02 03:04:05"#,
+                "2025-01-02 03:04:05[Europe/Paris]"
+                    .parse::<Zoned>()
+                    .unwrap(),
+            ),
+        ] {
+            assert_eq!(parse_build(input), expected, "{input}");
+        }
+    }
 }

src/items/offset.rs

@@ -0,0 +1,485 @@
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
+//! Parse an offset item.
+//!
+//! From the GNU docs:
+//!
+//! > A “time zone item” specifies an international time zone, indicated by a
+//! > small set of letters, e.g., ‘UTC’ or ‘Z’ for Coordinated Universal Time.
+//! > Any included periods are ignored.  By following a non-daylight-saving
+//! > time zone by the string ‘DST’ in a separate word (that is, separated by
+//! > some white space), the corresponding daylight saving time zone may be
+//! > specified.  Alternatively, a non-daylight-saving time zone can be
+//! > followed by a time zone correction, to add the two values.  This is
+//! > normally done only for ‘UTC’; for example, ‘UTC+05:30’ is equivalent to
+//! > ‘+05:30’.
+//! >
+//! >    Time zone items other than ‘UTC’ and ‘Z’ are obsolescent and are not
+//! > recommended, because they are ambiguous; for example, ‘EST’ has a
+//! > different meaning in Australia than in the United States, and ‘A’ has
+//! > different meaning as a military time zone than as an obsolete RFC 822
+//! > time zone.  Instead, it's better to use unambiguous numeric time zone
+//! > corrections like ‘-0500’, as described in the previous section.
+//! >
+//! >    If neither a time zone item nor a time zone correction is supplied,
+//! > timestamps are interpreted using the rules of the default time zone.
+
+use std::fmt::Display;
+
+use winnow::{
+    combinator::{alt, peek},
+    error::{ContextError, ErrMode},
+    stream::{AsChar, Stream},
+    token::take_while,
+    ModalResult, Parser,
+};
+
+use super::{
+    primitive::{colon, ctx_err, dec_uint, dec_uint_str, plus_or_minus, s},
+    relative,
+};
+
+/// Represents a time zone offset from UTC.
+///
+/// This struct is used to represent a time zone offset in hours and minutes,
+/// with a boolean indicating whether the offset is negative (i.e., west of
+/// UTC).
+#[derive(PartialEq, Debug, Clone, Default)]
+pub(super) struct Offset {
+    negative: bool,
+    hours: u8,
+    minutes: u8,
+}
+
+impl Offset {
+    /// Merge two timezone offsets.
+    ///
+    /// Note: when parsing an offset from a string (e.g., "+08:00"), the hours
+    /// and minutes are validated to ensure they fall within valid bounds. In
+    /// contrast, merging two offsets does not perform such validation. This
+    /// behavior is intentional to match GNU date.
+    fn merge(self, offset: Offset) -> Offset {
+        fn combine(a: u16, neg_a: bool, b: u16, neg_b: bool) -> (u16, bool) {
+            if neg_a == neg_b {
+                (a + b, neg_a)
+            } else if a > b {
+                (a - b, neg_a)
+            } else {
+                (b - a, neg_b)
+            }
+        }
+        let (total_minutes, negative) = combine(
+            (self.hours as u16) * 60 + (self.minutes as u16),
+            self.negative,
+            (offset.hours as u16) * 60 + (offset.minutes as u16),
+            offset.negative,
+        );
+        let hours = (total_minutes / 60) as u8;
+        let minutes = (total_minutes % 60) as u8;
+
+        Offset {
+            negative,
+            hours,
+            minutes,
+        }
+    }
+
+    /// Normalize the offset so that the hour field is within the accepted range.
+    ///
+    /// - If the hour field is less than 24, or exactly 24 with a zero minute,
+    ///   the offset is already normalized, and the function returns the offset
+    ///   itself along with a zero hour adjustment.
+    /// - Otherwise, the hour field is reduced to 23 while preserving the minute
+    ///   field, and the function returns the normalized offset along with the
+    ///   hour adjustment needed to reach the original offset.
+    pub(super) fn normalize(self) -> (Offset, i8) {
+        if self.hours < 24 || (self.hours == 24 && self.minutes == 0) {
+            return (self, 0);
+        }
+
+        let hour_adjustment = (self.hours as i8 - 23) * if self.negative { 1 } else { -1 };
+        (
+            Offset {
+                negative: self.negative,
+                hours: 23,
+                minutes: self.minutes,
+            },
+            hour_adjustment,
+        )
+    }
+
+    pub(super) fn total_seconds(&self) -> i32 {
+        let secs = (self.hours as i32) * 3600 + (self.minutes as i32) * 60;
+        if self.negative {
+            -secs
+        } else {
+            secs
+        }
+    }
+}
+
+impl TryFrom<(bool, u8, u8)> for Offset {
+    type Error = &'static str;
+
+    fn try_from((negative, hours, minutes): (bool, u8, u8)) -> Result<Self, Self::Error> {
+        if hours > 24 {
+            return Err("timezone hour must be between 0 and 24");
+        }
+        if minutes > 60 || (hours == 24 && minutes != 0) {
+            return Err("timezone minute must be between 0 and 60");
+        }
+
+        Ok(Offset {
+            negative,
+            hours,
+            minutes,
+        })
+    }
+}
+
+impl TryFrom<&Offset> for jiff::tz::TimeZone {
+    type Error = &'static str;
+
+    fn try_from(
+        Offset {
+            negative,
+            hours,
+            minutes,
+        }: &Offset,
+    ) -> Result<Self, Self::Error> {
+        let secs = (*hours as i32) * 3600 + (*minutes as i32) * 60;
+        let secs = if *negative { -secs } else { secs };
+
+        let offset = jiff::tz::Offset::from_seconds(secs).map_err(|_| "offset is invalid")?;
+        Ok(jiff::tz::TimeZone::fixed(offset))
+    }
+}
+
+impl Display for Offset {
+    fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
+        write!(
+            fmt,
+            "{}{:02}:{:02}",
+            if self.negative { "-" } else { "+" },
+            self.hours,
+            self.minutes
+        )
+    }
+}
+
+pub(super) fn parse(input: &mut &str) -> ModalResult<Offset> {
+    timezone_name_offset.parse_next(input)
+}
+
+/// Parse a timezone starting with `+` or `-`.
+pub(super) fn timezone_offset(input: &mut &str) -> ModalResult<Offset> {
+    // Strings like "+8 years" are ambiguous, they can either be parsed as a
+    // timezone offset "+8" and a relative time "years", or just a relative time
+    // "+8 years". GNU date parses them the second way, so we do the same here.
+    //
+    // Return early if the input can be parsed as a relative time.
+    if peek(relative::parse).parse_next(input).is_ok() {
+        return Err(ErrMode::Backtrack(ContextError::new()));
+    }
+
+    alt((timezone_offset_colon, timezone_offset_colonless)).parse_next(input)
+}
+
+/// Parse a timezone by name, with an optional numeric offset appended.
+fn timezone_name_offset(input: &mut &str) -> ModalResult<Offset> {
+    /// I'm assuming there are no timezone abbreviations with more
+    /// than 6 charactres
+    const MAX_TZ_SIZE: usize = 6;
+    let nextword = s(take_while(1..=MAX_TZ_SIZE, AsChar::is_alpha)).parse_next(input)?;
+    let tz = timezone_name_to_offset(nextword)?;
+
+    // Strings like "UTC +8 years" are ambiguous, they can either be parsed as
+    // "UTC+8" and "years", or "UTC" and "+8 years". GNU date parses them the
+    // second way, so we do the same here.
+    //
+    // Only process if the input cannot be parsed as a relative time.
+    if peek(relative::parse).parse_next(input).is_err() {
+        let start = input.checkpoint();
+        if let Ok(other_tz) = timezone_offset.parse_next(input) {
+            let new_tz = tz.merge(other_tz);
+
+            return Ok(new_tz);
+        };
+        input.reset(&start);
+    }
+
+    Ok(tz)
+}
+
+/// Parse a timezone offset with a colon separating hours and minutes, e.g.,
+/// `+08:00`, `+8:00`, `+8:0`.
+fn timezone_offset_colon(input: &mut &str) -> ModalResult<Offset> {
+    (plus_or_minus, s(dec_uint), s(colon), s(dec_uint))
+        .parse_next(input)
+        .and_then(|(sign, hours, _, minutes)| {
+            (sign == '-', hours, minutes)
+                .try_into()
+                .map_err(|e| ErrMode::Cut(ctx_err(e)))
+        })
+}
+
+/// Parse a timezone offset without colon, e.g., `+0800`, `+800`, `+08`, `+8`.
+fn timezone_offset_colonless(input: &mut &str) -> ModalResult<Offset> {
+    (plus_or_minus, s(dec_uint_str))
+        .verify_map(|(sign, s)| {
+            // GNU date accepts numeric offset strings with leading zeroes. For
+            // example, `+000000110` is valid. In such cases, the string is
+            // truncated to the last four characters. Thus, `+000000110` becomes
+            // `+0110` (note that one leading zero is kept).
+            let s = if s.len() > 4 && s.trim_start_matches('0').len() <= 4 {
+                &s[s.len() - 4..]
+            } else {
+                s
+            };
+
+            // Hour and minute values are dependent on the length of the string.
+            // For example:
+            //
+            // - "5"   -> 05:00
+            // - "05"  -> 05:00
+            // - "530" -> 05:30 (the minute is the last two characters here)
+            // - "0530"-> 05:30
+            // - "0000530" -> 05:30
+            let (h_str, m_str) = match s.len() {
+                1 | 2 => (s, "0"),
+                3 => s.split_at(1),
+                4 => s.split_at(2),
+                _ => return None,
+            };
+
+            let hours = h_str.parse::<u8>().ok()?;
+            let minutes = m_str.parse::<u8>().ok()?;
+            Some((sign, hours, minutes))
+        })
+        .parse_next(input)
+        .and_then(|(sign, hours, minutes)| {
+            (sign == '-', hours, minutes)
+                .try_into()
+                .map_err(|e| ErrMode::Cut(ctx_err(e)))
+        })
+}
+
+/// Named timezone list.
+///
+/// The full list of timezones can be extracted from
+/// https://www.timeanddate.com/time/zones/. GNU date only supports a subset of
+/// these. We support the same subset as GNU date.
+fn timezone_name_to_offset(input: &str) -> ModalResult<Offset> {
+    let mut offset_str = match input {
+        "z" => Ok("+0"),
+        "y" => Ok("-12"),
+        "x" => Ok("-11"),
+        "wet" => Ok("+0"),
+        "west" => Ok("+1"),
+        "wat" => Ok("+1"),
+        "w" => Ok("-10"),
+        "v" => Ok("-9"),
+        "utc" => Ok("+0"),
+        "u" => Ok("-8"),
+        "t" => Ok("-7"),
+        "sst" => Ok("-11"),
+        "sgt" => Ok("+8"),
+        "sast" => Ok("+2"),
+        "s" => Ok("-6"),
+        "r" => Ok("-5"),
+        "q" => Ok("-4"),
+        "pst" => Ok("-8"),
+        "pdt" => Ok("-7"),
+        "p" => Ok("-3"),
+        "o" => Ok("-2"),
+        "nzst" => Ok("+12"),
+        "nzdt" => Ok("+13"),
+        "nst" => Ok("-3:30"),
+        "ndt" => Ok("-2:30"),
+        "n" => Ok("-1"),
+        "mst" => Ok("-7"),
+        "msk" => Ok("+3"),
+        "msd" => Ok("+4"),
+        "mdt" => Ok("-6"),
+        "m" => Ok("+12"),
+        "l" => Ok("+11"),
+        "k" => Ok("+10"),
+        "jst" => Ok("+9"),
+        "ist" => Ok("+5:30"),
+        "i" => Ok("+9"),
+        "hst" => Ok("-10"),
+        "h" => Ok("+8"),
+        "gst" => Ok("+4"),
+        "gmt" => Ok("+0"),
+        "g" => Ok("+7"),
+        "f" => Ok("+6"),
+        "est" => Ok("-5"),
+        "eet" => Ok("+2"),
+        "eest" => Ok("+3"),
+        "edt" => Ok("-4"),
+        "eat" => Ok("+3"),
+        "e" => Ok("+5"),
+        "d" => Ok("+4"),
+        "cst" => Ok("-6"),
+        "clt" => Ok("-4"),
+        "clst" => Ok("-3"),
+        "cet" => Ok("+1"),
+        "cest" => Ok("+2"),
+        "cdt" => Ok("-5"),
+        "cat" => Ok("+2"),
+        "c" => Ok("+3"),
+        "bst" => Ok("+6"),
+        "brt" => Ok("-3"),
+        "brst" => Ok("-2"),
+        "b" => Ok("+2"),
+        "ast" => Ok("-3"),
+        "art" => Ok("-3"),
+        "akst" => Ok("-9"),
+        "akdt" => Ok("-8"),
+        "adt" => Ok("+4"),
+        "a" => Ok("+1"),
+        _ => Err(ErrMode::Backtrack(ContextError::new())),
+    }?;
+
+    timezone_offset(&mut offset_str)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn off(negative: bool, hours: u8, minutes: u8) -> Offset {
+        Offset {
+            negative,
+            hours,
+            minutes,
+        }
+    }
+
+    #[test]
+    fn timezone_offset_with_colon() {
+        for (input, expected) in [
+            ("+00:00", off(false, 0, 0)),        // UTC
+            ("-00:00", off(true, 0, 0)),         // UTC
+            ("+01:00", off(false, 1, 0)),        // positive offset
+            ("-06:00", off(true, 6, 0)),         // negative offset
+            ("+05:30", off(false, 5, 30)),       // positive offset with non-zero minutes
+            ("-03:30", off(true, 3, 30)),        // negative offset with non-zero minutes
+            ("- 06:00", off(true, 6, 0)),        // space after sign
+            ("- 06 : 00", off(true, 6, 0)),      // space around colon
+            ("+5:3", off(false, 5, 3)),          // single-digit hours and single-digit minutes
+            ("+5:03", off(false, 5, 3)),         // single-digit hours
+            ("+05:3", off(false, 5, 3)),         // single-digit minutes
+            ("+00005:00030", off(false, 5, 30)), // leading zeroes in hours and minutes
+            ("+00:00abc", off(false, 0, 0)), // space separator can be ignored if immediately followed by alphas (GNU date behavior)
+        ] {
+            let mut s = input;
+            assert_eq!(timezone_offset(&mut s).unwrap(), expected, "{input}");
+        }
+
+        for input in [
+            "+25:00", // invalid: hours > 24
+            "-23:61", // invalid: minutes > 60
+            "+24:01", // invalid: minutes > 0 when hours == 24
+        ] {
+            let mut s = input;
+            assert!(timezone_offset(&mut s).is_err(), "{input}");
+        }
+    }
+
+    #[test]
+    fn timezone_offset_without_colon() {
+        for (input, expected) in [
+            ("+0000", off(false, 0, 0)),      // UTC
+            ("-0000", off(true, 0, 0)),       // UTC
+            ("+0100", off(false, 1, 0)),      // positive offset
+            ("-0600", off(true, 6, 0)),       // negative offset
+            ("+0530", off(false, 5, 30)),     // positive offset with non-zero minutes
+            ("-0330", off(true, 3, 30)),      // negative offset with non-zero minutes
+            ("- 0330", off(true, 3, 30)),     // space after sign
+            ("+530", off(false, 5, 30)),      // single-digit hours
+            ("+05", off(false, 5, 0)),        // double-digit hours and no minutes
+            ("+5", off(false, 5, 0)),         // single-digit hours and no minutes
+            ("+00000530", off(false, 5, 30)), // leading zeroes
+            ("+0000abc", off(false, 0, 0)), // space separator can be ignored if immediately followed by alphas (GNU date behavior)
+        ] {
+            let mut s = input;
+            assert_eq!(timezone_offset(&mut s).unwrap(), expected, "{input}");
+        }
+
+        for input in [
+            "+2500",    // invalid: hours > 24
+            "-2361",    // invalid: minutes > 60
+            "+2401",    // invalid: minutes > 0 when hours == 24
+            "+23 days", // invalid: ambiguous with relative time parsing
+        ] {
+            let mut s = input;
+            assert!(timezone_offset(&mut s).is_err(), "{input}");
+        }
+    }
+
+    #[test]
+    fn timezone_name_without_offset() {
+        for (input, expected) in [
+            ("utc", off(false, 0, 0)),  // UTC
+            ("gmt", off(false, 0, 0)),  // UTC
+            ("z", off(false, 0, 0)),    // UTC
+            ("west", off(false, 1, 0)), // positive offset
+            ("cst", off(true, 6, 0)),   // negative offset
+            ("ist", off(false, 5, 30)), // positive offset with non-zero minutes
+            ("nst", off(true, 3, 30)),  // negative offset with non-zero minutes
+            ("z123", off(false, 0, 0)), // space separator can be ignored if immediately followed by digits (GNU date behavior)
+        ] {
+            let mut s = input;
+            assert_eq!(timezone_name_offset(&mut s).unwrap(), expected, "{input}");
+        }
+
+        for input in [
+            "abc",    // invalid: non-existent timezone
+            "utcabc", // invalid: non-existent timezone
+        ] {
+            let mut s = input;
+            assert!(timezone_name_offset(&mut s).is_err(), "{input}");
+        }
+    }
+
+    #[test]
+    fn timezone_name_with_offset() {
+        for (input, expected) in [
+            ("utc+5:30", off(false, 5, 30)),     // UTC with possitive offset
+            ("utc-5:30", off(true, 5, 30)),      // UTC with negative offset
+            ("utc +5:30", off(false, 5, 30)),    // space after timezone name
+            ("utc + 5 : 30", off(false, 5, 30)), // spaces
+            ("a+5:30", off(false, 6, 30)),       // merge two positive offsets (a=+1)
+            ("a-5:30", off(true, 4, 30)),        // merge positive and negative offsets (a=+1)
+            ("n-5:30", off(true, 6, 30)),        // merge two negative offsets (n=-1)
+            ("n+5:30", off(false, 4, 30)),       // merge negative and positive offsets (n=-1)
+            ("m+24", off(false, 36, 0)),         // maximum possible positive offset (m=+12)
+            ("y-24", off(true, 36, 0)),          // maximum possible negative offset (y=-12)
+        ] {
+            let mut s = input;
+            assert_eq!(timezone_name_offset(&mut s).unwrap(), expected, "{input}");
+        }
+
+        for input in [
+            "abc+08:00",   // invalid: non-existent timezone
+            "utc+25",      // invalid: invalid offset
+            "utc+23 days", // invalid: ambiguous with relative time parsing
+        ] {
+            let mut s = input;
+            assert!(
+                timezone_name_offset(&mut s).is_err() || !s.is_empty(),
+                "{input}"
+            );
+        }
+    }
+
+    #[test]
+    fn total_seconds() {
+        assert_eq!(off(false, 0, 0).total_seconds(), 0);
+        assert_eq!(off(false, 5, 30).total_seconds(), 19_800);
+        assert_eq!(off(true, 5, 30).total_seconds(), -19_800);
+        assert_eq!(off(false, 24, 0).total_seconds(), 86_400);
+    }
+}

src/items/primitive.rs

@@ -142,3 +142,64 @@ pub(super) fn ctx_err(reason: &'static str) -> ContextError {
     err.push(StrContext::Expected(StrContextValue::Description(reason)));
     err
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parse_dec_int() {
+        for (input, expected) in [
+            ("123", 123),                 // positive without sign
+            ("+123", 123),                // positive with '+' sign
+            ("-123", -123),               // negative with '-' sign
+            ("0", 0),                     // zero
+            ("+0", 0),                    // zero with '+' sign
+            ("-0", 0),                    // zero with '-' sign (parses as 0)
+            ("012", 12),                  // zero-prefixed (the main reason for this function)
+            ("+012", 12),                 // zero-prefixed with '+' sign
+            ("-012", -12),                // zero-prefixed with '-' sign
+            ("00123", 123),               // multiple leading zeros
+            ("2147483647", 2147483647),   // i32::MAX
+            ("-2147483648", -2147483648), // i32::MIN
+        ] {
+            let mut s = input;
+            assert_eq!(
+                dec_int::<ContextError>(&mut s).unwrap(),
+                expected,
+                "{input}"
+            );
+        }
+
+        for input in [
+            "",    // empty string
+            "+",   // sign without digits
+            "-",   // sign without digits
+            "abc", // non-numeric
+            "12a", // starts with digits but has non-digit after (but should parse "12" successfully)
+        ] {
+            let mut s = input;
+            let result = dec_int::<ContextError>(&mut s);
+            // Note: "12a" will actually succeed and parse "12", leaving "a" unparsed
+            if input == "12a" {
+                assert_eq!(result.unwrap(), 12, "{input}");
+                assert_eq!(s, "a", "Should leave 'a' unparsed");
+            } else {
+                assert!(result.is_err(), "{input} should fail");
+            }
+        }
+
+        // Test overflow cases
+        for input in [
+            "2147483648",  // i32::MAX + 1
+            "-2147483649", // i32::MIN - 1
+            "99999999999", // way too large
+        ] {
+            let mut s = input;
+            assert!(
+                dec_int::<ContextError>(&mut s).is_err(),
+                "{input} should overflow"
+            );
+        }
+    }
+}

src/items/relative.rs

@@ -83,7 +83,7 @@ pub(super) fn parse(input: &mut &str) -> ModalResult<Relative> {
 fn seconds(input: &mut &str) -> ModalResult<Relative> {
     (
         opt(alt((s('+').value(1), s('-').value(-1)))),
-        sec_and_nsec,
+        s(sec_and_nsec),
         s(alpha1).verify(|s: &str| matches!(s, "seconds" | "second" | "sec" | "secs")),
         ago,
     )
@@ -138,11 +138,13 @@ mod tests {
             ("secs", Relative::Seconds(1, 0)),
             ("second ago", Relative::Seconds(-1, 0)),
             ("3 seconds", Relative::Seconds(3, 0)),
+            ("+ 3 seconds", Relative::Seconds(3, 0)),
             ("3.5 seconds", Relative::Seconds(3, 500_000_000)),
             ("-3.5 seconds", Relative::Seconds(-4, 500_000_000)),
             ("+3.5 seconds", Relative::Seconds(3, 500_000_000)),
+            ("+ 3.5 seconds", Relative::Seconds(3, 500_000_000)),
             ("3.5 seconds ago", Relative::Seconds(-4, 500_000_000)),
-            ("-3.5 seconds ago", Relative::Seconds(3, 500_000_000)),
+            ("-  3.5 seconds ago", Relative::Seconds(3, 500_000_000)),
             // Minutes
             ("minute", Relative::Minutes(1)),
             ("minutes", Relative::Minutes(1)),
@@ -150,29 +152,40 @@ mod tests {
             ("mins", Relative::Minutes(1)),
             ("10 minutes", Relative::Minutes(10)),
             ("-10 minutes", Relative::Minutes(-10)),
+            ("- 10 minutes", Relative::Minutes(-10)),
             ("10 minutes ago", Relative::Minutes(-10)),
             ("-10 minutes ago", Relative::Minutes(10)),
+            ("- 10 minutes ago", Relative::Minutes(10)),
+            ("-10 minutes ago", Relative::Minutes(10)),
+            ("- 10 minutes ago", Relative::Minutes(10)),
             // Hours
             ("hour", Relative::Hours(1)),
             ("hours", Relative::Hours(1)),
             ("10 hours", Relative::Hours(10)),
             ("+10 hours", Relative::Hours(10)),
+            ("+ 10 hours", Relative::Hours(10)),
             ("-10 hours", Relative::Hours(-10)),
+            ("- 10 hours", Relative::Hours(-10)),
             ("10 hours ago", Relative::Hours(-10)),
             ("-10 hours ago", Relative::Hours(10)),
+            ("- 10 hours ago", Relative::Hours(10)),
             // Days
             ("day", Relative::Days(1)),
             ("days", Relative::Days(1)),
             ("10 days", Relative::Days(10)),
             ("+10 days", Relative::Days(10)),
+            ("+ 10 days", Relative::Days(10)),
             ("-10 days", Relative::Days(-10)),
+            ("- 10 days", Relative::Days(-10)),
             ("10 days ago", Relative::Days(-10)),
             ("-10 days ago", Relative::Days(10)),
+            ("- 10 days ago", Relative::Days(10)),
             // Multiple days
             ("fortnight", Relative::Days(14)),
             ("fortnights", Relative::Days(14)),
             ("2 fortnights ago", Relative::Days(-28)),
             ("+2 fortnights ago", Relative::Days(-28)),
+            ("+ 2 fortnights ago", Relative::Days(-28)),
             ("week", Relative::Days(7)),
             ("weeks", Relative::Days(7)),
             ("2 weeks ago", Relative::Days(-14)),

src/items/time.rs

@@ -45,8 +45,8 @@ use winnow::{
 
 use super::{
     epoch::sec_and_nsec,
+    offset::{timezone_offset, Offset},
     primitive::{colon, ctx_err, dec_uint, s},
-    timezone::{timezone_offset, Offset},
 };
 
 #[derive(PartialEq, Clone, Debug, Default)]