実行した日が誕生日だったらHappy Birthdayとprintするだけのスクリプト ref: http://qiita.com/jollyjoester/items/06b2d375e19cff3a8c27

HappyBirthDay.swift

let name = "俺様"

let birthdayComponents = NSDateComponents()
birthdayComponents.year = 1982
birthdayComponents.month = 1
birthdayComponents.day = 18

if let calendar = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian) {
    if let birthday = calendar.dateFromComponents(birthdayComponents) {
        let now = NSDate()
        let elapsed = calendar.components(([.Year, .Month, .Day]), fromDate: birthday, toDate: now, options: [])

        let year = elapsed.year
        let month = elapsed.month
        let day = elapsed.day

        switch (month, day) {
        case (0, 0):
            print("A Happy \(year)th birthday to \(name)🎉")
        default:
            print("A very mery unbirthday to you!")
        }
    }
}