Scholiday

A tiny Scala library that contains holiday rules that can be leveraged for date time calculations. This library provides a type class that supports JDK 8 date instances. Plan to support Joda LocalDate, LocalDateTime, DateTime instances in the future.

NOTE: This is a very early version of this library that I created quickly. You can expect significant changes in future versions.

The trait io.scholiday.Holidays defines configurations for regional holidays. Given an implicit instance of Holidays in scope, the IsHoliday typeclass can tell you if a given day is a holiday. Currently, only rules for US Federal holidays (see io.scholiday.regions.UsFederalHolidays) are implemented. I plan to implement rules for other regions in the future. It is pretty straightforward to create a Holidays instance for another region yourself in the main time - feel free to contribute a pull request.

Usage

libraryDependencies += "com.github.farhankaz" %% "scholiday" % 0.0.1"

  import io.scholiday._
  // import holiday rules for your region
  import io.scholiday.regions.UsFederalHolidays._

  // Christmas holiday on the 25th of December, unless 25th falls on Saturday or Sunday.
  val christmas2018 = LocalDate.of(2018, 12, 25)
  assert(christmas2018.isHoliday == true)

  // Thanksgiving holiday is always the 4th Thursday in November
  val thanksGiving2018 = LocalDate.of(2018, 11, 22)
  assert(thanksGiving2018.isHoliday == true)

  // Random non-holiday
  val sameRandomDay = LocalDate.of(2018, 12, 12)
  assert(sameRandomDay.isHoliday == false)

Supported holiday rules

Currently, this library provides rules for US Federal holidays. These are the straightforward rules:

• New Years: January 1st unless 1st is Saturday/Sunday. If so, offset forward to first business day
• Birthday of Martin Luther King Jr. Day: Third Monday in January
• Washington's Birthday: Third Monday in February
• Memorial Day: Last Monday in May
• Independence Day: July 4th unless 4th is Saturday/Sunday. If so, offset to a business day
• Labor Day: First Monday in September
• Columbus Day: Second Monday in October
• Veteran's Day: Nov 11th unless 11th is Saturday/Sunday. If so, offset to a business day
• Thanksgiving Day: Fourth Thursday in November
• Christmas Day: Dec 25th unless 25th is Saturday/Sunday. If so, offset to a business day

Some outstanding questions..

• Should JDK's Locale be used to retrieve a given locality's holiday rules?