NSDate day of the year (swift)

Question

How might the day number of the year be found with swift? Is there a simple way that I'm not seeing, or do I have to find the number of seconds from Jan 1 to the current date and divide by the number of seconds in a day?

Answer 1

This is a translation of the answer to How do you calculate the day of the year for a specific date in Objective-C? to Swift.

Swift 2:

let date = NSDate() // now let cal = NSCalendar.currentCalendar() let day = cal.ordinalityOfUnit(.Day, inUnit: .Year, forDate: date) print(day) 

Swift 3:

let date = Date() // now let cal = Calendar.current let day = cal.ordinality(of: .day, in: .year, for: date) print(day) 

This gives 1 for the first day in the year, and 56 = 31 + 25 for today (Feb 25).

... or do I have to find the number of seconds from Jan 1 to the current date and divide by the number of seconds in a day

This would be a wrong approach, because a day does not have a fixed number of seconds (transition from or to Daylight Saving Time).

Answer 2

Swift 3

extension Date {     var dayOfYear: Int {         return Calendar.current.ordinality(of: .day, in: .year, for: self)!     } } 

use like

Date().dayOfYear