Converting UTC date format to local nsdate

Question

I am getting from my server a string date in UTC time zone and I need to convert it to the local time zone.

MY CODE:

let utcTime = "2015-04-01T11:42:00.269Z"     let dateFormatter = NSDateFormatter() dateFormatter.timeZone = NSTimeZone(name: "UTC") dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'" let date = dateFormatter.dateFromString(utcTime) println("utc: \(utcTime), date: \(date)") 

this prints -

utc: 2015-04-01T11:42:00.269Z, date: Optional(2015-04-01 11:42:00 +0000)

if I remove

dateFormatter.timeZone = NSTimeZone(name: "UTC")  

it prints

utc: 2015-04-01T11:42:00.269Z, date: Optional(2015-04-01 08:42:00 +0000)

my local time zone is UTC +3 and in the first option I get UTC in the second option I get UTC -3

I should get

utc: 2015-04-01T11:42:00.269Z, date: Optional(2015-04-01 14:42:00 +0000)

So how do I convert the UTC date format to local time?

Answer 1

Something along the following worked for me in Objective-C :

// create dateFormatter with UTC time format NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; [dateFormatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss"];  [dateFormatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"UTC"]]; NSDate *date = [dateFormatter dateFromString:@"2015-04-01T11:42:00"]; // create date from string  // change to a readable time format and change to local time zone [dateFormatter setDateFormat:@"EEE, MMM d, yyyy - h:mm a"]; [dateFormatter setTimeZone:[NSTimeZone localTimeZone]]; NSString *timestamp = [dateFormatter stringFromDate:date]; 

I keep these two websites handy for converting different time formats: http://www.w3.org/TR/NOTE-datetime

http://benscheirman.com/2010/06/dealing-with-dates-time-zones-in-objective-c/

In Swift it will be:

// create dateFormatter with UTC time format   let dateFormatter = DateFormatter()         dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"         dateFormatter.timeZone = NSTimeZone(name: "UTC") as TimeZone?         let date = dateFormatter.date(from: "2015-04-01T11:42:00")// create   date from string          // change to a readable time format and change to local time zone         dateFormatter.dateFormat = "EEE, MMM d, yyyy - h:mm a"         dateFormatter.timeZone = NSTimeZone.local         let timeStamp = dateFormatter.string(from: date!) 

Answer 2

Try this Swift extension

Swift 4: UTC/GMT ⟺ Local (Current/System)

extension Date {      // Convert local time to UTC (or GMT)     func toGlobalTime() -> Date {         let timezone = TimeZone.current         let seconds = -TimeInterval(timezone.secondsFromGMT(for: self))         return Date(timeInterval: seconds, since: self)     }      // Convert UTC (or GMT) to local time     func toLocalTime() -> Date {         let timezone = TimeZone.current         let seconds = TimeInterval(timezone.secondsFromGMT(for: self))         return Date(timeInterval: seconds, since: self)     }  }   // Try it let utcDate = Date().toGlobalTime() let localDate = utcDate.toLocalTime()  print("utcDate - \(utcDate)")        //Print UTC Date print("localDate - \(localDate)")     //Print Local Date