PoshCode Archive  Artifact [f824f83266]

Artifact f824f832665f45b6c1a83714f1709ede111022dc447ba08077073ff5688fbd4f:

• File Get-EasterWestern.ps1 — part of check-in [edcaaf78f8] at 2018-06-10 13:27:05 on branch trunk — Calculates the Gregorian Easter date for a given year. (user: michaelvdnest size: 1674)

# encoding: ascii
# api: powershell
# title: Get-EasterWestern
# description: Calculates the Gregorian Easter date for a given year.
# version: 0.1
# type: function
# author: michaelvdnest
# license: CC0
# function: Get-EasterWestern
# x-poshcode-id: 3527
# x-archived: 2012-07-20T07:34:34
# x-published: 2012-07-18T02:24:00
#
#
function Get-EasterWestern {
	Param(
		[Parameter(Mandatory=$true)]
        [int] $Year
 	)

	
	$a = $Year % 19

	$b = [Math]::Floor($Year / 100)

	$c = $Year % 100

	$d = [Math]::Floor($b / 4)

	$e = $b % 4

	$f = [Math]::Floor(($b + 8) / 25)

	$g = [Math]::Floor((($b - $f + 1) / 3))
	
	$h = ((19 * $a) + $b + (-$d) + (-$g) + 15) % 30

	$i = [Math]::Floor($c / 4)

	$k = $c % 4

	$L1 = -($h + $k) #here because powershell is picking up - (subtraction operator) as incorrect toekn
	$L = (32 + (2 * $e) + (2 * $i) + $L1) % 7

	$m = [Math]::Floor(($a + (11 * $h) + (22 * $L)) / 451)

	$v1 = -(7 * $m) #here because powershell is picking up - (subtraction operator) as incorrect toekn
	$month = [Math]::Floor(($h + $L + $v1 + 114) / 31)

	$day = (($h + $L + $v1 + 114) % 31) + 1

	[System.DateTime]$date = "$Year/$month/$day"
	
	$date
	
	<#
		.SYNOPSIS
			Calculates the Gregorian Easter date for a given year.

		.DESCRIPTION
			Calculates the Gregorian Easter date for a given year greater than 1751. Algorithm sourced from http://en.wikipedia.org/wiki/Computus, Anonymous Gregorian algorithm. 
			
		.PARAMETER Year
			The year to calculate easter for.

		.EXAMPLE
			PS C:\> Get-EasterWestern 2017

		.INPUTS
			System.Int32

		.OUTPUTS
			System.DateTime
	#>
	
	
}