From 8b56d1572fec145d2bafc21c319de3ee6230a37d Mon Sep 17 00:00:00 2001
From: labbots <admin@labbots.com>
Date: Sun, 7 Jun 2020 20:10:07 +0100
Subject: [PATCH] Added date functions

---
 README.md              | 895 +++++++++++++++++++++++++++++++++++++++++
 bash_utilities.sh      |   1 +
 bin/generate_readme.sh |   2 +
 src/date.sh            | 769 +++++++++++++++++++++++++++++++++++
 src/file.sh            |   4 +-
 5 files changed, 1669 insertions(+), 2 deletions(-)
 create mode 100644 src/date.sh

diff --git a/README.md b/README.md
index d74aed1..a190813 100644
--- a/README.md
+++ b/README.md
@@ -17,6 +17,39 @@ Bash library which provides utility functions and helpers for functional program
   - [array::join()](#arrayjoin)
   - [array::reverse()](#arrayreverse)
   - [array::random_element()](#arrayrandom_element)
+- [Date](#date)
+  - [date::now()](#datenow)
+  - [date::epoc()](#dateepoc)
+  - [date::add_days_from()](#dateadd_days_from)
+  - [date::add_months_from()](#dateadd_months_from)
+  - [date::add_years_from()](#dateadd_years_from)
+  - [date::add_weeks_from()](#dateadd_weeks_from)
+  - [date::add_hours_from()](#dateadd_hours_from)
+  - [date::add_minutes_from()](#dateadd_minutes_from)
+  - [date::add_seconds_from()](#dateadd_seconds_from)
+  - [date::add_days()](#dateadd_days)
+  - [date::add_months()](#dateadd_months)
+  - [date::add_years()](#dateadd_years)
+  - [date::add_weeks()](#dateadd_weeks)
+  - [date::add_hours()](#dateadd_hours)
+  - [date::add_minutes()](#dateadd_minutes)
+  - [date::add_seconds()](#dateadd_seconds)
+  - [date::sub_days_from()](#datesub_days_from)
+  - [date::sub_months_from()](#datesub_months_from)
+  - [date::sub_years_from()](#datesub_years_from)
+  - [date::sub_weeks_from()](#datesub_weeks_from)
+  - [date::sub_hours_from()](#datesub_hours_from)
+  - [date::sub_minutes_from()](#datesub_minutes_from)
+  - [date::sub_seconds_from()](#datesub_seconds_from)
+  - [date::sub_days()](#datesub_days)
+  - [date::sub_months()](#datesub_months)
+  - [date::sub_years()](#datesub_years)
+  - [date::sub_weeks()](#datesub_weeks)
+  - [date::sub_hours()](#datesub_hours)
+  - [date::sub_minutes()](#datesub_minutes)
+  - [date::sub_seconds()](#datesub_seconds)
+  - [date::format()](#dateformat)
+  - [date::human_readable_seconds()](#datehuman_readable_seconds)
 - [File](#file)
   - [file::make_temp_file()](#filemake_temp_file)
   - [file::name()](#filename)
@@ -209,6 +242,868 @@ c
 
 - Random item out of the array.
 
+## Date
+
+Functions for manipulating dates.
+
+### date::now()
+
+Get current time in unix timestamp.
+
+#### Example
+
+```bash
+echo "$(date::now)"
+#Output
+1591554426
+```
+
+*Function has no arguments.*
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+
+#### Output on stdout
+
+- current timestamp.
+
+### date::epoc()
+
+convert datetime string to unix timestamp.
+
+#### Example
+
+```bash
+echo "$(date::epoc "2020-07-07 18:38")"
+#Output
+1594143480
+```
+
+#### Arguments
+
+- **$1** (string): date time in any format.
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- timestamp for specified datetime.
+
+### date::add_days_from()
+
+Add number of days from specified timestamp.
+If number of days not specified then it defaults to 1 day.
+
+#### Example
+
+```bash
+echo "$(date::add_days_from "1594143480")"
+#Output
+1594229880
+```
+
+#### Arguments
+
+- **$1** (int): unix timestamp.
+- **$2** (int): number of days (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::add_months_from()
+
+Add number of months from specified timestamp.
+If number of months not specified then it defaults to 1 month.
+
+#### Example
+
+```bash
+echo "$(date::add_months_from "1594143480")"
+#Output
+1596821880
+```
+
+#### Arguments
+
+- **$1** (int): unix timestamp.
+- **$2** (int): number of months (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::add_years_from()
+
+Add number of years from specified timestamp.
+If number of years not specified then it defaults to 1 year.
+
+#### Example
+
+```bash
+echo "$(date::add_years_from "1594143480")"
+#Output
+1625679480
+```
+
+#### Arguments
+
+- **$1** (int): unix timestamp.
+- **$2** (int): number of years (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::add_weeks_from()
+
+Add number of weeks from specified timestamp.
+If number of weeks not specified then it defaults to 1 week.
+
+#### Example
+
+```bash
+echo "$(date::add_weeks_from "1594143480")"
+#Output
+1594748280
+```
+
+#### Arguments
+
+- **$1** (int): unix timestamp.
+- **$2** (int): number of weeks (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::add_hours_from()
+
+Add number of hours from specified timestamp.
+If number of hours not specified then it defaults to 1 hour.
+
+#### Example
+
+```bash
+echo "$(date::add_hours_from "1594143480")"
+#Output
+1594147080
+```
+
+#### Arguments
+
+- **$1** (int): unix timestamp.
+- **$2** (int): number of hours (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::add_minutes_from()
+
+Add number of minutes from specified timestamp.
+If number of minutes not specified then it defaults to 1 minute.
+
+#### Example
+
+```bash
+echo "$(date::add_minutes_from "1594143480")"
+#Output
+1594143540
+```
+
+#### Arguments
+
+- **$1** (int): unix timestamp.
+- **$2** (int): number of minutes (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::add_seconds_from()
+
+Add number of seconds from specified timestamp.
+If number of seconds not specified then it defaults to 1 second.
+
+#### Example
+
+```bash
+echo "$(date::add_seconds_from "1594143480")"
+#Output
+1594143481
+```
+
+#### Arguments
+
+- **$1** (int): unix timestamp.
+- **$2** (int): number of seconds (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::add_days()
+
+Add number of days from current day timestamp.
+If number of days not specified then it defaults to 1 day.
+
+#### Example
+
+```bash
+echo "$(date::add_days "1")"
+#Output
+1591640826
+```
+
+#### Arguments
+
+- **$1** (int): number of days (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::add_months()
+
+Add number of months from current day timestamp.
+If number of months not specified then it defaults to 1 month.
+
+#### Example
+
+```bash
+echo "$(date::add_months "1")"
+#Output
+1594146426
+```
+
+#### Arguments
+
+- **$1** (int): number of months (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::add_years()
+
+Add number of years from current day timestamp.
+If number of years not specified then it defaults to 1 year.
+
+#### Example
+
+```bash
+echo "$(date::add_years "1")"
+#Output
+1623090426
+```
+
+#### Arguments
+
+- **$1** (int): number of years (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::add_weeks()
+
+Add number of weeks from current day timestamp.
+If number of weeks not specified then it defaults to 1 year.
+
+#### Example
+
+```bash
+echo "$(date::add_weeks "1")"
+#Output
+1592159226
+```
+
+#### Arguments
+
+- **$1** (int): number of weeks (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::add_hours()
+
+Add number of hours from current day timestamp.
+If number of hours not specified then it defaults to 1 hour.
+
+#### Example
+
+```bash
+echo "$(date::add_hours "1")"
+#Output
+1591558026
+```
+
+#### Arguments
+
+- **$1** (int): number of hours (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::add_minutes()
+
+Add number of minutes from current day timestamp.
+If number of minutes not specified then it defaults to 1 minute.
+
+#### Example
+
+```bash
+echo "$(date::add_minutes "1")"
+#Output
+1591554486
+```
+
+#### Arguments
+
+- **$2** (int): number of minutes (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::add_seconds()
+
+Add number of seconds from current day timestamp.
+If number of seconds not specified then it defaults to 1 second.
+
+#### Example
+
+```bash
+echo "$(date::add_seconds "1")"
+#Output
+1591554427
+```
+
+#### Arguments
+
+- **$2** (int): number of seconds (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::sub_days_from()
+
+Subtract number of days from specified timestamp.
+If number of days not specified then it defaults to 1 day.
+
+#### Example
+
+```bash
+echo "$(date::sub_days_from "1594143480")"
+#Output
+1594057080
+```
+
+#### Arguments
+
+- **$1** (int): unix timestamp.
+- **$2** (int): number of days (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::sub_months_from()
+
+Subtract number of months from specified timestamp.
+If number of months not specified then it defaults to 1 month.
+
+#### Example
+
+```bash
+echo "$(date::sub_months_from "1594143480")"
+#Output
+1591551480
+```
+
+#### Arguments
+
+- **$1** (int): unix timestamp.
+- **$2** (int): number of months (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::sub_years_from()
+
+Subtract number of years from specified timestamp.
+If number of years not specified then it defaults to 1 year.
+
+#### Example
+
+```bash
+echo "$(date::sub_years_from "1594143480")"
+#Output
+1562521080
+```
+
+#### Arguments
+
+- **$1** (int): unix timestamp.
+- **$2** (int): number of years (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::sub_weeks_from()
+
+Subtract number of weeks from specified timestamp.
+If number of weeks not specified then it defaults to 1 week.
+
+#### Example
+
+```bash
+echo "$(date::sub_weeks_from "1594143480")"
+#Output
+1593538680
+```
+
+#### Arguments
+
+- **$1** (int): unix timestamp.
+- **$2** (int): number of weeks (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::sub_hours_from()
+
+Subtract number of hours from specified timestamp.
+If number of hours not specified then it defaults to 1 hour.
+
+#### Example
+
+```bash
+echo "$(date::sub_hours_from "1594143480")"
+#Output
+1594139880
+```
+
+#### Arguments
+
+- **$1** (int): unix timestamp.
+- **$2** (int): number of hours (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::sub_minutes_from()
+
+Subtract number of minutes from specified timestamp.
+If number of minutes not specified then it defaults to 1 minute.
+
+#### Example
+
+```bash
+echo "$(date::sub_minutes_from "1594143480")"
+#Output
+1594143420
+```
+
+#### Arguments
+
+- **$1** (int): unix timestamp.
+- **$2** (int): number of minutes (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::sub_seconds_from()
+
+Subtract number of seconds from specified timestamp.
+If number of seconds not specified then it defaults to 1 second.
+
+#### Example
+
+```bash
+echo "$(date::sub_seconds_from "1594143480")"
+#Output
+1594143479
+```
+
+#### Arguments
+
+- **$1** (int): unix timestamp.
+- **$2** (int): number of seconds (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::sub_days()
+
+Subtract number of days from current day timestamp.
+If number of days not specified then it defaults to 1 day.
+
+#### Example
+
+```bash
+echo "$(date::sub_days "1")"
+#Output
+1588876026
+```
+
+#### Arguments
+
+- **$1** (int): number of days (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::sub_months()
+
+Subtract number of months from current day timestamp.
+If number of months not specified then it defaults to 1 month.
+
+#### Example
+
+```bash
+echo "$(date::sub_months "1")"
+#Output
+1559932026
+```
+
+#### Arguments
+
+- **$1** (int): number of months (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::sub_years()
+
+Subtract number of years from current day timestamp.
+If number of years not specified then it defaults to 1 year.
+
+#### Example
+
+```bash
+echo "$(date::sub_years "1")"
+#Output
+1591468026
+```
+
+#### Arguments
+
+- **$1** (int): number of years (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::sub_weeks()
+
+Subtract number of weeks from current day timestamp.
+If number of weeks not specified then it defaults to 1 week.
+
+#### Example
+
+```bash
+echo "$(date::sub_weeks "1")"
+#Output
+1590949626
+```
+
+#### Arguments
+
+- **$1** (int): number of weeks (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::sub_hours()
+
+Subtract number of hours from current day timestamp.
+If number of hours not specified then it defaults to 1 hour.
+
+#### Example
+
+```bash
+echo "$(date::sub_hours "1")"
+#Output
+1591550826
+```
+
+#### Arguments
+
+- **$1** (int): number of hours (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::sub_minutes()
+
+Subtract number of minutes from current day timestamp.
+If number of minutes not specified then it defaults to 1 minute.
+
+#### Example
+
+```bash
+echo "$(date::sub_minutes "1")"
+#Output
+1591554366
+```
+
+#### Arguments
+
+- **$1** (int): number of minutes (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::sub_seconds()
+
+Subtract number of seconds from current day timestamp.
+If number of seconds not specified then it defaults to 1 second.
+
+#### Example
+
+```bash
+echo "$(date::sub_seconds "1")"
+#Output
+1591554425
+```
+
+#### Arguments
+
+- **$1** (int): number of seconds (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate timestamp.
+
+#### Output on stdout
+
+- timestamp.
+
+### date::format()
+
+Format unix timestamp to human readable format.
+If format string is not specified then it defaults to "yyyy-mm-dd hh:mm:ss" format.
+
+#### Example
+
+```bash
+echo echo "$(date::format "1594143480")"
+#Output
+2020-07-07 18:38:00
+```
+
+#### Arguments
+
+- **$1** (int): unix timestamp.
+- **$2** (string): format control characters based on `date` command (optional).
+
+#### Exit codes
+
+- **0**:  If successful.
+- **1**: If unable to generate time string.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- formatted time string.
+
+### date::human_readable_seconds()
+
+Format seconds to human readable format.
+
+#### Example
+
+```bash
+echo "$(date::human_readable_seconds "356786")"
+#Output
+4 days 3 hrs 6 minute(s) and 26 seconds
+```
+
+#### Arguments
+
+- **$1** (int): number of seconds.
+
+#### Exit codes
+
+- **0**:  If successful.
+- **2**: Function missing arguments.
+
+#### Output on stdout
+
+- formatted time string.
+
 ## File
 
 Functions for handling files.
diff --git a/bash_utilities.sh b/bash_utilities.sh
index 71e3e3b..358863c 100644
--- a/bash_utilities.sh
+++ b/bash_utilities.sh
@@ -5,3 +5,4 @@ source src/string.sh
 source src/variable.sh
 source src/file.sh
 source src/misc.sh
+source src/date.sh
diff --git a/bin/generate_readme.sh b/bin/generate_readme.sh
index 384d5e8..533e474 100755
--- a/bin/generate_readme.sh
+++ b/bin/generate_readme.sh
@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+#https://github.com/bkrem/make-toc.sh/blob/master/make-toc.sh
+#https://gitlab.com/pedrolab/doctoc.sh/-/blob/master/doctoc.sh
 _usage() {
     printf "
 Script to autogenerate markdown based on bash source code.\n
diff --git a/src/date.sh b/src/date.sh
new file mode 100644
index 0000000..255f99d
--- /dev/null
+++ b/src/date.sh
@@ -0,0 +1,769 @@
+#!/usr/bin/env bash
+
+# @file Date
+# @brief Functions for manipulating dates.
+
+# @description Get current time in unix timestamp.
+#
+# @example
+#   echo "$(date::now)"
+#   #Output
+#   1591554426
+#
+# @noargs
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+#
+# @stdout current timestamp.
+date::now() {
+    declare now
+    now="$(date --universal +%s)" || return $?
+    printf "%s" "${now}"
+}
+
+# @description convert datetime string to unix timestamp.
+#
+# @example
+#   echo "$(date::epoc "2020-07-07 18:38")"
+#   #Output
+#   1594143480
+#
+# @arg $1 string date time in any format.
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout timestamp for specified datetime.
+date::epoc() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare input date
+    date=$(date -d "${1}" +"%s") || return $?
+    printf "%s" "${date}"
+}
+
+# @description Add number of days from specified timestamp.
+# If number of days not specified then it defaults to 1 day.
+#
+# @example
+#   echo "$(date::add_days_from "1594143480")"
+#   #Output
+#   1594229880
+#
+# @arg $1 int unix timestamp.
+# @arg $2 int number of days (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout timestamp.
+date::add_days_from() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare timestamp new_timestamp day
+    timestamp="${1}"
+    day=${2:-1}
+    new_timestamp="$(date -d "$(date -d "@${timestamp}" '+%F %T')+${day} day" +'%s')" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Add number of months from specified timestamp.
+# If number of months not specified then it defaults to 1 month.
+#
+# @example
+#   echo "$(date::add_months_from "1594143480")"
+#   #Output
+#   1596821880
+#
+# @arg $1 int unix timestamp.
+# @arg $2 int number of months (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout timestamp.
+date::add_months_from() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare timestamp new_timestamp month
+    timestamp="${1}"
+    month=${2:-1}
+    new_timestamp="$(date -d "$(date -d "@${timestamp}" '+%F %T')+${month} month" +'%s')" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Add number of years from specified timestamp.
+# If number of years not specified then it defaults to 1 year.
+#
+# @example
+#   echo "$(date::add_years_from "1594143480")"
+#   #Output
+#   1625679480
+#
+# @arg $1 int unix timestamp.
+# @arg $2 int number of years (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout timestamp.
+date::add_years_from() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare timestamp new_timestamp year
+    timestamp="${1}"
+    year=${2:-1}
+    new_timestamp="$(date -d "$(date -d "@${timestamp}" '+%F %T')+${year} year" +'%s')" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Add number of weeks from specified timestamp.
+# If number of weeks not specified then it defaults to 1 week.
+#
+# @example
+#   echo "$(date::add_weeks_from "1594143480")"
+#   #Output
+#   1594748280
+#
+# @arg $1 int unix timestamp.
+# @arg $2 int number of weeks (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout timestamp.
+date::add_weeks_from() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare timestamp new_timestamp week
+    timestamp="${1}"
+    week=${2:-1}
+    new_timestamp="$(date -d "$(date -d "@${timestamp}" '+%F %T')+${week} week" +'%s')" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Add number of hours from specified timestamp.
+# If number of hours not specified then it defaults to 1 hour.
+#
+# @example
+#   echo "$(date::add_hours_from "1594143480")"
+#   #Output
+#   1594147080
+#
+# @arg $1 int unix timestamp.
+# @arg $2 int number of hours (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout timestamp.
+date::add_hours_from() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare timestamp new_timestamp hour
+    timestamp="${1}"
+    hour=${2:-1}
+    new_timestamp="$(date -d "$(date -d "@${timestamp}" '+%F %T')+${hour} hour" +'%s')" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Add number of minutes from specified timestamp.
+# If number of minutes not specified then it defaults to 1 minute.
+#
+# @example
+#   echo "$(date::add_minutes_from "1594143480")"
+#   #Output
+#   1594143540
+#
+# @arg $1 int unix timestamp.
+# @arg $2 int number of minutes (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout timestamp.
+date::add_minutes_from() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare timestamp new_timestamp minute
+    timestamp="${1}"
+    minute=${2:-1}
+    new_timestamp="$(date -d "$(date -d "@${timestamp}" '+%F %T')+${minute} minute" +'%s')" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Add number of seconds from specified timestamp.
+# If number of seconds not specified then it defaults to 1 second.
+#
+# @example
+#   echo "$(date::add_seconds_from "1594143480")"
+#   #Output
+#   1594143481
+#
+# @arg $1 int unix timestamp.
+# @arg $2 int number of seconds (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout timestamp.
+date::add_seconds_from() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare timestamp new_timestamp minute
+    timestamp="${1}"
+    second=${2:-1}
+    new_timestamp="$(date -d "$(date -d "@${timestamp}" '+%F %T')+${second} second" +'%s')" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Add number of days from current day timestamp.
+# If number of days not specified then it defaults to 1 day.
+#
+# @example
+#   echo "$(date::add_days "1")"
+#   #Output
+#   1591640826
+#
+# @arg $1 int number of days (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+#
+# @stdout timestamp.
+date::add_days() {
+    declare timestamp new_timestamp day
+    timestamp="$(date::now)"
+    day=${1:-1}
+    new_timestamp="$(date::add_days_from "${timestamp}" "${second}")" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Add number of months from current day timestamp.
+# If number of months not specified then it defaults to 1 month.
+#
+# @example
+#   echo "$(date::add_months "1")"
+#   #Output
+#   1594146426
+#
+# @arg $1 int number of months (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+#
+# @stdout timestamp.
+date::add_months() {
+    declare timestamp new_timestamp month
+    timestamp="$(date::now)"
+    month=${1:-1}
+    new_timestamp="$(date::add_months_from "${timestamp}" "${second}")" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Add number of years from current day timestamp.
+# If number of years not specified then it defaults to 1 year.
+#
+# @example
+#   echo "$(date::add_years "1")"
+#   #Output
+#   1623090426
+#
+# @arg $1 int number of years (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+#
+# @stdout timestamp.
+date::add_years() {
+    declare timestamp new_timestamp year
+    timestamp="$(date::now)"
+    year=${1:-1}
+    new_timestamp="$(date::add_years_from "${timestamp}" "${second}")" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Add number of weeks from current day timestamp.
+# If number of weeks not specified then it defaults to 1 year.
+#
+# @example
+#   echo "$(date::add_weeks "1")"
+#   #Output
+#   1592159226
+#
+# @arg $1 int number of weeks (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+#
+# @stdout timestamp.
+date::add_weeks() {
+    declare timestamp new_timestamp week
+    timestamp="$(date::now)"
+    week=${1:-1}
+    new_timestamp="$(date::add_weeks_from "${timestamp}" "${second}")" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Add number of hours from current day timestamp.
+# If number of hours not specified then it defaults to 1 hour.
+#
+# @example
+#   echo "$(date::add_hours "1")"
+#   #Output
+#   1591558026
+#
+# @arg $1 int number of hours (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+#
+# @stdout timestamp.
+date::add_hours() {
+    declare timestamp new_timestamp hour
+    timestamp="$(date::now)"
+    hour=${1:-1}
+    new_timestamp="$(date::add_hours_from "${timestamp}" "${second}")" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Add number of minutes from current day timestamp.
+# If number of minutes not specified then it defaults to 1 minute.
+#
+# @example
+#   echo "$(date::add_minutes "1")"
+#   #Output
+#   1591554486
+#
+# @arg $2 int number of minutes (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+#
+# @stdout timestamp.
+date::add_minutes() {
+    declare timestamp new_timestamp minute
+    timestamp="$(date::now)"
+    minute=${1:-1}
+    new_timestamp="$(date::add_minutes_from "${timestamp}" "${second}")" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Add number of seconds from current day timestamp.
+# If number of seconds not specified then it defaults to 1 second.
+#
+# @example
+#   echo "$(date::add_seconds "1")"
+#   #Output
+#   1591554427
+#
+# @arg $2 int number of seconds (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+#
+# @stdout timestamp.
+date::add_seconds() {
+    declare timestamp new_timestamp minute
+    timestamp="$(date::now)"
+    second=${1:-1}
+    new_timestamp="$(date::add_seconds_from "${timestamp}" "${second}")" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Subtract number of days from specified timestamp.
+# If number of days not specified then it defaults to 1 day.
+#
+# @example
+#   echo "$(date::sub_days_from "1594143480")"
+#   #Output
+#   1594057080
+#
+# @arg $1 int unix timestamp.
+# @arg $2 int number of days (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout timestamp.
+date::sub_days_from() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare timestamp new_timestamp day
+    timestamp="${1}"
+    day=${2:-1}
+    new_timestamp="$(date -d "$(date -d "@${timestamp}" '+%F %T') ${day} days ago" +'%s')" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Subtract number of months from specified timestamp.
+# If number of months not specified then it defaults to 1 month.
+#
+# @example
+#   echo "$(date::sub_months_from "1594143480")"
+#   #Output
+#   1591551480
+#
+# @arg $1 int unix timestamp.
+# @arg $2 int number of months (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout timestamp.
+date::sub_months_from() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare timestamp new_timestamp month
+    timestamp="${1}"
+    month=${2:-1}
+    new_timestamp="$(date -d "$(date -d "@${timestamp}" '+%F %T') ${month} months ago" +'%s')" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Subtract number of years from specified timestamp.
+# If number of years not specified then it defaults to 1 year.
+#
+# @example
+#   echo "$(date::sub_years_from "1594143480")"
+#   #Output
+#   1562521080
+#
+# @arg $1 int unix timestamp.
+# @arg $2 int number of years (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout timestamp.
+date::sub_years_from() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare timestamp new_timestamp year
+    timestamp="${1}"
+    year=${2:-1}
+    new_timestamp="$(date -d "$(date -d "@${timestamp}" '+%F %T') ${year} years ago" +'%s')" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Subtract number of weeks from specified timestamp.
+# If number of weeks not specified then it defaults to 1 week.
+#
+# @example
+#   echo "$(date::sub_weeks_from "1594143480")"
+#   #Output
+#   1593538680
+#
+# @arg $1 int unix timestamp.
+# @arg $2 int number of weeks (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout timestamp.
+date::sub_weeks_from() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare timestamp new_timestamp week
+    timestamp="${1}"
+    week=${2:-1}
+    new_timestamp="$(date -d "$(date -d "@${timestamp}" '+%F %T') ${week} weeks ago" +'%s')" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Subtract number of hours from specified timestamp.
+# If number of hours not specified then it defaults to 1 hour.
+#
+# @example
+#   echo "$(date::sub_hours_from "1594143480")"
+#   #Output
+#   1594139880
+#
+# @arg $1 int unix timestamp.
+# @arg $2 int number of hours (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout timestamp.
+date::sub_hours_from() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare timestamp new_timestamp hour
+    timestamp="${1}"
+    hour=${2:-1}
+    new_timestamp="$(date -d "$(date -d "@${timestamp}" '+%F %T') ${hour} hours ago" +'%s')" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Subtract number of minutes from specified timestamp.
+# If number of minutes not specified then it defaults to 1 minute.
+#
+# @example
+#   echo "$(date::sub_minutes_from "1594143480")"
+#   #Output
+#   1594143420
+#
+# @arg $1 int unix timestamp.
+# @arg $2 int number of minutes (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout timestamp.
+date::sub_minutes_from() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare timestamp new_timestamp minute
+    timestamp="${1}"
+    minute=${2:-1}
+    new_timestamp="$(date -d "$(date -d "@${timestamp}" '+%F %T') ${minute} minutes ago" +'%s')" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Subtract number of seconds from specified timestamp.
+# If number of seconds not specified then it defaults to 1 second.
+#
+# @example
+#   echo "$(date::sub_seconds_from "1594143480")"
+#   #Output
+#   1594143479
+#
+# @arg $1 int unix timestamp.
+# @arg $2 int number of seconds (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout timestamp.
+date::sub_seconds_from() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare timestamp new_timestamp minute
+    timestamp="${1}"
+    second=${2:-1}
+    new_timestamp="$(date -d "$(date -d "@${timestamp}" '+%F %T') ${second} seconds ago" +'%s')" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Subtract number of days from current day timestamp.
+# If number of days not specified then it defaults to 1 day.
+#
+# @example
+#   echo "$(date::sub_days "1")"
+#   #Output
+#   1588876026
+#
+# @arg $1 int number of days (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+#
+# @stdout timestamp.
+date::sub_days() {
+    declare timestamp new_timestamp day
+    timestamp="$(date::now)"
+    day=${1:-1}
+    new_timestamp="$(date::sub_days_from "${timestamp}" "${second}")" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Subtract number of months from current day timestamp.
+# If number of months not specified then it defaults to 1 month.
+#
+# @example
+#   echo "$(date::sub_months "1")"
+#   #Output
+#   1559932026
+#
+# @arg $1 int number of months (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+#
+# @stdout timestamp.
+date::sub_months() {
+    declare timestamp new_timestamp month
+    timestamp="$(date::now)"
+    month=${1:-1}
+    new_timestamp="$(date::sub_months_from "${timestamp}" "${second}")" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Subtract number of years from current day timestamp.
+# If number of years not specified then it defaults to 1 year.
+#
+# @example
+#   echo "$(date::sub_years "1")"
+#   #Output
+#   1591468026
+#
+# @arg $1 int number of years (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+#
+# @stdout timestamp.
+date::sub_years() {
+    declare timestamp new_timestamp year
+    timestamp="$(date::now)"
+    year=${1:-1}
+    new_timestamp="$(date::sub_years_from "${timestamp}" "${second}")" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Subtract number of weeks from current day timestamp.
+# If number of weeks not specified then it defaults to 1 week.
+#
+# @example
+#   echo "$(date::sub_weeks "1")"
+#   #Output
+#   1590949626
+#
+# @arg $1 int number of weeks (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+#
+# @stdout timestamp.
+date::sub_weeks() {
+    declare timestamp new_timestamp week
+    timestamp="$(date::now)"
+    week=${1:-1}
+    new_timestamp="$(date::sub_weeks_from "${timestamp}" "${second}")" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Subtract number of hours from current day timestamp.
+# If number of hours not specified then it defaults to 1 hour.
+#
+# @example
+#   echo "$(date::sub_hours "1")"
+#   #Output
+#   1591550826
+#
+# @arg $1 int number of hours (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+#
+# @stdout timestamp.
+date::sub_hours() {
+    declare timestamp new_timestamp hour
+    timestamp="$(date::now)"
+    hour=${1:-1}
+    new_timestamp="$(date::sub_hours_from "${timestamp}" "${second}")" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Subtract number of minutes from current day timestamp.
+# If number of minutes not specified then it defaults to 1 minute.
+#
+# @example
+#   echo "$(date::sub_minutes "1")"
+#   #Output
+#   1591554366
+#
+# @arg $1 int number of minutes (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+#
+# @stdout timestamp.
+date::sub_minutes() {
+    declare timestamp new_timestamp minute
+    timestamp="$(date::now)"
+    minute=${1:-1}
+    new_timestamp="$(date::sub_minutes_from "${timestamp}" "${second}")" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Subtract number of seconds from current day timestamp.
+# If number of seconds not specified then it defaults to 1 second.
+#
+# @example
+#   echo "$(date::sub_seconds "1")"
+#   #Output
+#   1591554425
+#
+# @arg $1 int number of seconds (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate timestamp.
+#
+# @stdout timestamp.
+date::sub_seconds() {
+    declare timestamp new_timestamp minute
+    timestamp="$(date::now)"
+    second=${1:-1}
+    new_timestamp="$(date::sub_seconds_from "${timestamp}" "${second}")" || return $?
+    printf "%s" "${new_timestamp}"
+}
+
+# @description Format unix timestamp to human readable format.
+# If format string is not specified then it defaults to "yyyy-mm-dd hh:mm:ss" format.
+#
+# @example
+#   echo echo "$(date::format "1594143480")"
+#   #Output
+#   2020-07-07 18:38:00
+#
+# @arg $1 int unix timestamp.
+# @arg $2 string format control characters based on `date` command (optional).
+#
+# @exitcode 0  If successful.
+# @exitcode 1 If unable to generate time string.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout formatted time string.
+date::format() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare timestamp format out
+    timestamp="${1}"
+    format="${2:-"%F %T"}"
+    out="$(date -d "@${timestamp}" +"${format}")" || return $?
+    printf "%s" "${out}"
+
+}
+
+# @description Format seconds to human readable format.
+#
+# @example
+#   echo "$(date::human_readable_seconds "356786")"
+#   #Output
+#   4 days 3 hrs 6 minute(s) and 26 seconds
+#
+# @arg $1 int number of seconds.
+#
+# @exitcode 0  If successful.
+# @exitcode 2 Function missing arguments.
+#
+# @stdout formatted time string.
+date::human_readable_seconds() {
+    [[ $# = 0 ]] && printf "%s: Missing arguments\n" "${FUNCNAME[0]}" && return 2
+
+    declare T="${1}"
+    declare DAY="$((T / 60 / 60 / 24))" HR="$((T / 60 / 60 % 24))" MIN="$((T / 60 % 60))" SEC="$((T % 60))"
+    [[ ${DAY} -gt 0 ]] && printf '%d days ' "${DAY}"
+    [[ ${HR} -gt 0 ]] && printf '%d hrs ' "${HR}"
+    [[ ${MIN} -gt 0 ]] && printf '%d minute(s) ' "${MIN}"
+    [[ ${DAY} -gt 0 || ${HR} -gt 0 || ${MIN} -gt 0 ]] && printf 'and '
+    printf '%d seconds\n' "${SEC}"
+}
diff --git a/src/file.sh b/src/file.sh
index 9ad526c..8879ede 100644
--- a/src/file.sh
+++ b/src/file.sh
@@ -25,7 +25,7 @@ file::make_temp_file() {
 }
 
 # @description Get only the filename from string path.
-
+#
 # @example
 #   echo "$(file::name "/path/to/test.md")"
 #   #Output
@@ -43,7 +43,7 @@ file::name() {
 }
 
 # @description Get the basename of file from file name.
-
+#
 # @example
 #   echo "$(file::basename "/path/to/test.md")"
 #   #Output