hebcal

https://github.com/betesh/hebcal

# HebCal Determines the date of Passover for a Gregorian year. Also includes boolean functions to check whether a date is a Jewish holiday, Fast Day or Rosh Chodesh. Supported languages: Javascript Ruby ## Installation as a Ruby gem Add this line to your application's Gemfile: gem 'hebcal' And then execute: $ bundle Or install it yourself as: $ gem install hebcal ## General notes 1. 3- and 4-digit years are supported, so the domain of valid years is 100-9999. For years before the Gregorian transition (1582), the transition is ignored and the proleptic Gregorian calendar is used. ## Ruby Version ### To Run Unit Tests $ rake test ### To Use #### Calculating the date of Passover 1. At the top of the file where the class is defined, declare `require `hebcal`` 1. In the class, declare `include HebCal::Passover` 1. `WhenIsPesach(yyyy)` returns a Ruby Time object representing midnight on the first day of passover, where `yyyy` is the Gregorian year Note that the date returned is the first day of Pesach, not the day on which Pesach begins at sunset. #### Finding out if a date is a holiday 1. At the top of the file where the class is defined, declare `require `hebcal`` 1. In the desired class, declare `include HebCal::Holidays` 1. `IsPesach(d)` returns true iff d is a Ruby Time object representing a date during Pesach. Note that the day on which Pesach begins at sunset returns false. 1. The following functions work in a similar way to `IsPesach()`: 1. `IsShavuot()`, `IsRoshHashanah()`, `IsYomKippur()`, `IsSukkot()` 1. `IsRegel()`: `IsPesach() || IsShavuot || IsSukkot()` 1. `IsMoed()`: Hol HaMoed Pesach or Hol HaMoed Sukkot 1. `IsYomTov()`: `IsPesach() || IsShavuot() || IsRoshHashanah() || IsSukkot()) && !IsMoed()` Note that IsYomTov(yk) == false, where yk is the date of Yom Kippur. 1. `IsPurim()`, `IsHanuka()` 1. `Is10Tevet()`, `IsTaanitEster()`, `Is17Tamuz()`, `Is9Av()`, `IsFastOfGedalia()` 1. `IsTaanit()`: `Is10Tevet() || IsTaanitEster() || Is17Tamuz() || Is9Av()...