Get UTC time and local time from NSDate object

Question

In objective-c, the following code results in the UTC date time information using the date API.

NSDate *currentUTCDate = [NSDate date]


        

Answer 1

I found an easier way to get UTC in Swift4. Put this code in playground

let date = Date() 
*//"Mar 15, 2018 at 4:01 PM"*

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss ZZZ"
dateFormatter.timeZone = TimeZone(secondsFromGMT: 0)

let newDate = dateFormatter.string(from: date) 
*//"2018-03-15 21:05:04 +0000"*

Answer 2

Swift 3

You can get Date based on your current timezone from UTC

extension Date {
    func currentTimeZoneDate() -> String {
        let dtf = DateFormatter()
        dtf.timeZone = TimeZone.current
        dtf.dateFormat = "yyyy-MM-dd HH:mm:ss"

        return dtf.string(from: self)
    }
}

Call like this:

Date().currentTimeZoneDate()

Answer 3

My Xcode Version 6.1.1 (6A2008a)

In playground, test like this:

// I'm in East Timezone 8
let x = NSDate() //Output:"Dec 29, 2014, 11:37 AM"
let y = NSDate.init() //Output:"Dec 29, 2014, 11:37 AM"
println(x) //Output:"2014-12-29 03:37:24 +0000"


// seconds since 2001
x.hash //Output:441,517,044
x.hashValue //Output:441,517,044
x.timeIntervalSinceReferenceDate //Output:441,517,044.875367

// seconds since 1970
x.timeIntervalSince1970 //Output:1,419,824,244.87537

Answer 4

In addition to other answers, you can write an extension for Date class to get formatted Data in specific TimeZone to make it as utility function for future use. Like

 extension Date {

 func dateInTimeZone(timeZoneIdentifier: String, dateFormat: String) -> String  {
 let dtf = DateFormatter()
 dtf.timeZone = TimeZone(identifier: timeZoneIdentifier)
 dtf.dateFormat = dateFormat

 return dtf.string(from: self)
 }
}

Now you can call it like

 Date().dateInTimeZone(timeZoneIdentifier: "UTC", dateFormat: "yyyy-MM-dd HH:mm:ss");