Swift Playground #1 adding components to Date using operator overloading.

Dates.playground

import Foundation

extension Int{
    var day: (Int, Calendar.Component) {
        return (self, .day)
    }
    
    var month: (Int, Calendar.Component) {
        return (self, .month)
    }
    
    var year: (Int, Calendar.Component) {
        return (self, .year)
    }
}

////
public func + (date: Date, tuple: (value: Int, unit: Calendar.Component)) -> Date {
    return Calendar.current.date(byAdding: tuple.unit, value: tuple.value, to: date)!
}

public func - (date: Date, tuple: (value: Int, unit: Calendar.Component))  -> Date {
    return Calendar.current.date(byAdding: tuple.unit, value: (-tuple.value), to: date)!
}

public func += (date: inout Date, tuple: (value: Int, unit: Calendar.Component)) {
    date = Calendar.current.date(byAdding: tuple.unit, value: tuple.value, to: date)!
}

public func -= (date: inout Date, tuple: (value: Int, unit: Calendar.Component)) {
    date = Calendar.current.date(byAdding: tuple.unit, value: (-tuple.value), to: date)!
}


var tomorrow = Date() + 1.year
tomorrow += 1.day

var yesterday = Date() - 1.day
yesterday -= 1.year

you could sweeten this up a bit by adding extensions to Int

extension Int  {
    var day: (Int, NSCalendarUnit) {
        return (self, NSCalendarUnit.CalendarUnitDay)
    }
}

This allows you to do:

var tomorrow = NSDate() + 1.day
tomorrow += 1.day

I like these overloaded operations. Very nice.

What is the last argument options: NSCalendarOptions.SearchBackwards in dateByAddingUnit?
I was looking around, and I see that other people in similar answers use options: NSCalendarOptions(0), or options: nil, but no one explains what it does. And I cannot find it in Apple's documentation.

Ive updated this to bring it into swift 1.2 and taken derrh input to add and extension on Int to make the end api cleaner.

As for the Calendar option I have changed it to the only one documented by apple. Which added no real impact on the return of the method

Swift 3 doesn't have dateByAddingUnit.

`dateByAddingUnitseems to have been replaced by:Calendar.current.date(byAdding: .day, value: days, to: date)!`` Although, I can't find options anymore?

It's fixed now.

This is the worst code I've ever seen