Get NSDate and convert it from the 24 hour format to 12 hour format in swift

Question

I've seen this post for other languages but not for swift. I have a date saved in the format of 2015-08-31 21:36:00 +0000 and I'm able to extract the day, month, year and weekday with the code below to produce Monday, August 31, 2015. When I try to use:

let hourInt = components.hour
var hourString = String(hourInt)

It prints a four hour difference. In this case "17" for the "21". How do I display it as 9:36 P.M.?

let flags: NSCalendarUnit =  NSCalendarUnit.CalendarUnitMinute | NSCalendarUnit.CalendarUnitHour |  NSCalendarUnit.CalendarUnitDay | NSCalendarUnit.CalendarUnitWeekday | NSCalendarUnit.CalendarUnitMonth | NSCalendarUnit.CalendarUnitYear
let date = NSDate()
let dateFormatter: NSDateFormatter = NSDateFormatter()
let components = NSCalendar.currentCalendar().components(flags, fromDate: array.date)


let weekday = components.weekday
let weekdays = dateFormatter.weekdaySymbols
let weekdayString = weekdays[weekday-1] as! String

let month = components.month
let months = dateFormatter.monthSymbols
let monthString = months[month-1] as! String

let dayInt = components.day
var dayString = String(dayInt)

let year = components.year
let yearString = String(year)
println(weekdayString + ", " + monthString + " " + dayString + ", " + yearString)

Answer 1

Your date string suffix +0000 means it is UTC time if you want to display time at UTC you need to specify it when setting your date formatter.

let dateString = "2015-08-31 21:36:00 +0000"
let df = NSDateFormatter()
df.dateFormat = "yyyy-MM-dd HH:mm:ss Z"
if let date = df.dateFromString(dateString) {
    // now you have your date object
    // to display UTC time you have to specify timeZOne UTC
    df.timeZone = NSTimeZone(forSecondsFromGMT: 0)
    df.dateFormat = "EEEE, MMMM dd, yyyy h:mm:ss a"
    let stringFromDate = df.stringFromDate(date)
    println(stringFromDate)   // "Monday, August 31, 2015 9:36:00 PM"
}