Elixir Holidays

Elixir application for finding which holidays fall on given dates.

Based on the Holidays Ruby Gem

Source on GitHub

Installation

Add holidays to your list of dependencies in mix.exs:

def deps do
  [{:holidays, "~> 0.2.4"}]
end

Usage

1. The :holidays application must be started.

2. Initialize the definition modules you want to use. This may be one of the modules defined in this application or you may define your own.

   Holidays.Definitions.Us.init()

3. Call the on function, passing in a date and a list of regions.

   iex> Holidays.on({2016, 1, 1}, [:us]) [%{name: "New Year's Day"}]

The on function gives a list of holidays for a date within specified regions.

Dates in Erlang (and therefore Elixir) are represented by the {year, month, day} tuple.

Regions are often country codes, like :us or :ca, but may also be entities such as UPS (:ups) or the New York Stock Exchange (:nyse). They can sometimes also be states/provinces, like :us_ca or :us_dc.

Holidays are defined within modules in the lib/holidays/definitions directory which use the holiday function from Holidays.Define.

Contributions

It's fairly easy to take yaml files from the original Ruby implementation and translate them into the Elixir definition modules. The yaml files are included in the root definitions folder. That would be a great place to contribute if there is a region you need which hasn't been translated yet. Just be sure to include some tests. There's even a handy holiday_test macro to make it super simple to assert that the expected holiday is returned on the given date and region.

The Holidays.DateCalculator.WeekendModifier contains functions ported from Ruby to support the observed property as found in the original project, but this hasn't been implemented in the on function yet. The property does exist in the definition modules that have been translated so far.

The other feature from the Ruby project that could be implemented is the ability to specify a date range for the on function.

Also, if you have suggestions for anything I've done that doesn't make sense or could be done better, please let met know or send a pull request.