Xcode Swift am/pm time to 24 hour format

Question

I am trying to convert an am/pm format time to a 24 hour format time

6:35 PM to 18:35 

I tried this piece of code on playground but it doesn't seem to work if I put the time alone

let dateAsString = "02/12/15, 6:35 PM" let dateFormatter = NSDateFormatter() dateFormatter.dateFormat = "HH" let date = dateFormatter.dateFromString(dateAsString) //returns nil 

Does anyone know how to accomplish this?

Answer 1

Just convert it to a date using NSDateFormatter and the "h:mm a" format and convert it back to a string using the "HH:mm" format. Check out this date formatting guide to familiarize yourself with this material.

let dateAsString = "6:35 PM" let dateFormatter = NSDateFormatter() dateFormatter.dateFormat = "h:mm a" dateFormatter.locale = Locale(identifier: "en_US_POSIX") // fixes nil if device time in 24 hour format let date = dateFormatter.dateFromString(dateAsString)  dateFormatter.dateFormat = "HH:mm" let date24 = dateFormatter.stringFromDate(date!)