parse_datetime

A Rust crate for parsing human-readable relative time strings and human-readable datetime strings.

Features

• Parses a variety of human-readable and standard time formats.
• Supports positive and negative durations.
• Allows for chaining time units (e.g., "1 hour 2 minutes" or "2 days 2 hours ago").
• Calculate durations relative to a specified date.
• Relies on Jiff

Usage

Add parse_datetime to your Cargo.toml with:

cargo add parse_datetime

Then, import the crate and use the parse_datetime_at_date function:

use jiff::{ToSpan, Zoned};
use parse_datetime::{parse_datetime_at_date, ParsedDateTime};

let now = Zoned::now();
let after = parse_datetime_at_date(now.clone(), "+3 days");

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:

use jiff::{civil::{date, time} ,Zoned};
use parse_datetime::{parse_datetime, ParsedDateTime};

let dt = parse_datetime("2021-02-14 06:37:47");
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:

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

The parse_datetime and parse_datetime_at_date functions support absolute datetime and the following relative times:

• num unit (e.g., "-1 hour", "+3 days")
• unit (e.g., "hour", "day")
• "now" or "today"
• "yesterday"
• "tomorrow"
• use "ago" for the past
• use "next" or "last" with unit (e.g., "next week", "last year")
• unix timestamps (for example "@0" "@1344000")

num can be a positive or negative integer. unit can be one of the following: "fortnight", "week", "day", "hour", "minute", "min", "second", "sec" and their plural forms.

Return Values

parse_datetime and parse_datetime_at_date

The parse_datetime and parse_datetime_at_date function return:

• 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

To run the fuzzer:

$ cd fuzz
$ cargo install cargo-fuzz
$ cargo +nightly fuzz run fuzz_parse_datetime

License

This project is licensed under the MIT License.

Note

At some point, this crate was called humantime_to_duration. It has been renamed to cover more cases.