Format String for Elm
=====================
by Max Goldstein

Create format strings for dates in the Elm programming language.

Documentation
-------------

The module `Date.Format` exports `format : String -> Date.Date -> String`.
The `Date` refers to Elm's standard [Date library](http://package.elm-lang.org/packages/elm-lang/core/latest/Date).
The input `String` may contain any of the following substrings, which will be expanded to parts of the date.

* `%Y` - 4 digit year
* `%m` - Zero-padded month of year, e.g. `"07"` for July
* `%B` - Full month name, e.g. `"July"`
* `%b` - Abbreviated month name, e.g. `"Jul"`
* `%d` - Zero-padded day of month, e.g `"02"`
* `%e` - Space-padded day of month, e.g `" 2"`
* `%a` - Day of week, abbreviated to three letters, e.g. `"Wed"`
* `%A` - Day of week in full, e.g. `"Wednesday"`
* `%H` - Hour of the day, 24-hour clock, zero-padded
* `%k` - Hour of the day, 24-hour clock, space-padded
* `%I` - Hour of the day, 12-hour clock, zero-padded
* `%l` - (lower ell) Hour of the day, 12-hour clock, space-padded
* `%p` - AM or PM
* `%P` - am or pm
* `%M` - Minute of the hour, zero-padded
* `%S` - Second of the minute, zero-padded

Note that `%%` is intended to produce a literal `%` but this is not supported yet.

Contributing
------------

Pull requests are welcome! Note that in addition to adding a new letter to the
massive case statement, you'll also need to add it to the regex. Languages like
[Haskell](http://www.haskell.org/ghc/docs/6.12.3/html/libraries/time-1.1.4/Data-Time-Format.html),
[Python](https://docs.python.org/2/library/datetime.html#strftime-strptime-behavior),
and [Ruby](http://apidock.com/ruby/DateTime/strftime) have very comprehensive
format strings. (Luckily, they seem to agree on the encoding, which you should
follow.) The goal here is different: address 90% of use cases with relative
ease. So don't go adding formats just because they're there.