An ISO 8601 date formatting and parsing library for Erlang

• About
• Usage
• Known Deficiencies
• License

The erlang_iso8601 library was originally created by Sean Sawyer in 2011. In 2016, Sean handed off maintenance of the library to the erlsci Github org at which point the project (and repo) was renamed to simply iso8601, matching its Erlang app name:

• git clone https://github.com/erlsci/iso8601.git

Thanks to Github's forwarding for project renames and moves, the following still work:

• git clone https://github.com/seansawyer/erlang_iso8601.git
• git clone https://github.com/erlsci/erlang_iso8601.git

Add it to your rebar.config deps:

{iso8601, {git, "https://github.com/erlsci/iso8601.git", {tag, "1.3.2"}}}

Format a timestamp or calendar datetime tuple:

1> iso8601:format(now()).
<<"2012-02-16T01:06:19Z">>
2> iso8601:format(calendar:universal_time()).
<<"2012-02-16T01:06:48Z">>

Parse a date string or binary:

3> iso8601:parse(<<"2012-02-16T01:06:48Z">>).
{{2012,2,16},{1,6,48}}
4> iso8601:parse("2012-02-16T01:06:48Z").
{{2012,2,16},{1,6,48}}

Add 1 hour, 2 minutes and 3 seconds to a datetime tuple:

5> Datetime = iso8601:parse(<<"2012-02-16T01:06:48Z">>).
{{2012,2,16},{1,6,48}}
6> iso8601:add_time(Datetime, 1, 2, 3).
{{2012,2,16},{2,8,51}}

Subtract 1 hour, 2 minutes and 3 seconds from a datetime tuple:

5> Datetime = iso8601:parse(<<"2012-02-16T01:06:48Z">>).
{{2012,2,16},{1,6,48}}
6> iso8601:subtract_time(Datetime, 1, 2, 3).
{{2012,2,16},{0,4,45}}

Fractional times:

7> iso8601:parse("20120203T040506.50").
{{2012,2,3},{4,5,7}}
8> iso8601:parse_exact("20120203T040506.50").
{{2012,2,3},{4,5,6.50}}

Parse durations:

9> iso8601:parse_duration("+P6Y3M1DT1H1M1.1S").
[{sign, "+"}, {years, 6}, {months, 3}, {days, 1}, {hours, 1}, {minutes, 1}, {seconds, 1}]
10> iso8601:parse_duration("PT6M").
[{sign, []}, {years, 0}, {months, 0}, {days, 0},{hours, 0}, {minutes, 6}, {seconds, 0}]

• Does not support expanded year representation.
• Does not support intervals.

See the open issues for more info.

A donation account for supporting development on this project has been set up on Liberapay here:

• https://liberapay.com/erlsci-iso8601/donate

You can learn more about Liberapay on its Wikipedia entry or on the service's "About" page.

The MIT License (MIT)

Copyright © 2011-2014, Sean Sawyer
Copyright © 2012, Tristan Sloughter
Copyright © 2016-2021, Erlang-Aided Enrichment Center