[erlang-questions] [ANN] qdate - Unified Date Formatting/Parsing and Timezone Management

[Jesse Gumm]

Hello Erlangers,

I'm proud to announce the beta release (v0.1.0) of "qdate" - a unified date parsing/formatting and timezone management utility for Erlang.

Blog post describing my thoughts that went into its development

http://sigma-star.com/blog/post/qdate

Source code on GitHub (includes a README that covers all the functionality)

https://github.com/choptastic/qdate

At its core, qdate is basically a wrapper around ec_date (fork of dh_date and part of erlware_commons) and erlang_localtime.

But it's much more than just a wrapper. It's the complete date and time utility I feel is greatly needed in the Erlang world (since I found myself needing it).

Briefly, here's what it does:

* Easily convert from any date format to any other date format: datetime(), now(), unix timestamp, and formatted date strings (list and binaries) are all acceptable:

    > qdate:to_string("Y-m-d g:ia", Date).

    "2012-12-21 5:51pm"

    > qdate:to_string(<<"Y-m-d g:ia">>, Date).

    <<"2012-12-21 5:51pm">>

    > qdate:to_unixtime(Date).

    1356112260

    > qdate:to_date(Date).

    {{2012,12,21},{17,51,0}}

    > qdate:to_now(Date).

    {1356,112260,0}

    % Note, that the argument `Date` can be anything 

    % that's a Date/Time Format (datetime Tuple, now tuple,

    % Integer (unixtime), or string ("2012-12-21 5:51pm")

* Extends ec_date's formatting functions to include PHP's timezone-related characters:

   > qdate:to_string("Y-m-d g:ia T", Date)

   "2012-12-21 5:51pm CST"

* Able to pre-parse timezones from text strings, and convert from one timezone to another:

  % Read Timezone from string, convert to datetime in EST

   > qdate:to_date("2012-12-21 5:51pm CST","EST").

   {{2012,12,21},{18,51,0}}

   % Read timezone from string, convert to a string in EST

   > qdate:to_string("n/j/Y g:ia T","2012-12-21 5:51pm CST", "EST").

   "12/21/2012 6:51pm EST"

* Register timezones with the qdate server by a key (to make a timezone alias) or by pid():

   %% Set timezone for the current process to GMT

   > qdate:set_timezone("GMT").

   %% Set timezone for some_key to HKT

   > qdate:set_timezone(some_key, "HKT").

* Register custom formatting strings with the qdate server, for quick reference.

    > qdate:register_format(long_date, "l, F jS, Y g:i A T").

    ok

    > qdate:to_string(long_date,1356133860).

    "Friday, December 21st, 2012 11:51 PM GMT"

* Register custom parsing functions with the qdate server, to be transparently used for conversion.

      > qdate:register_parser(weird_format, fun parse_esoteric_format/1).

     ok

     > qdate:to_date("20121221.115100").

     {{2012,12,21},{11,51,00}}

* Attempt to maintain API compatibility with ec_date by supporting qdate:parse, qdate:nparse, and qdate:format.

I hope some of you find this useful in your apps.

Any issues, comments, complaints, bug reports, whatever, feel free to post in this thread, make a github issue, shoot me a message on twitter (@jessegumm) or email me directly.

Thanks, and I hope everyone has a glorious day or evening or whatever timezone you happen to be in.

--
Jesse Gumm
Owner, Sigma Star Systems
414.940.4866 || sigma-star.com || @jessegumm

[Dmitrii Dimandt]

Have you also looked at tempo, https://github.com/selectel/tempo ?

Your library and tempo could probably be combined

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[Jesse Gumm]

Hi Dmitrii,

I had not looked into tempo (I was not aware of its existence). Given that qdate is fundamentally a wrapper, I could see adding an option to change formatting backend to tempo (qdate currently uses ec_date as the backend for both parsing and formatting).

Thank you, I appreciate the suggestion,

-Jesse

[David Mercer]

Enh, I would tend to prefer Jesse’s qdate because it is pure Erlang.

 

Cheers,

 

DBM