Calculate Easter day in Swift

EasterDay.swift

import UIKit

func easterDay(Y : Int) -> NSDate {
	let a: Int = Y % 19
	let b: Int = Int(floor(Double(Y) / 100))
	let c: Int = Y % 100
	let d: Int = (19 * a + b - Int(floor(Double(b) / 4)) - Int(floor(Double(b - Int(floor(Double(b + 8) / 25)) + 1) / 3)) + 15) % 30
	let e: Int = (32 + 2 * (b % 4) + 2 * Int(floor(Double(c) / 4)) - d - (c % 4)) % 7
	let f: Int = Int(floor(Double(a + 11 * d + 22 * e) / 451))

	let components = NSDateComponents()
	components.year = Y
	components.month = Int(floor(Double(d + e - 7 * f + 114) / 31))
	components.day = ((d + e - 7 * f + 114) % 31) + 1
	components.timeZone = NSTimeZone(forSecondsFromGMT: 0)

	let cal = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)
	return cal!.dateFromComponents(components)!
}

print(easterDay(2016))