Creating Date object from timestamp in Swift [duplicate] - swift

Question

I get a crash when running and it points at the dateFormmater.timezone.
The error in the console is:
Could not cast value of type 'Swift.Optional' (0x1192bf4a8) to 'NSTimeZone' (0x1192c0270).
the value of rowEvents.date is "1480134638.0"
Im trying to pull out a Unix timestamp from Firebase saved as a string. Convert it to Date and again save it as a string so I can post it on a cell label.
I got this code from StackOverflow. I plugged in my data and everything is all good until I run it. I guess everything is not all good...
if let lastUpdated : String = rowEvents.date {
let epocTime = TimeInterval(lastUpdated)! / 1000 // convert it from milliseconds dividing it by 1000
let unixTimestamp = NSDate(timeIntervalSince1970: epocTime) //convert unix timestamp to Date
let dateFormatter = DateFormatter()
dateFormatter.timeZone = NSTimeZone() as TimeZone!
dateFormatter.locale = NSLocale.current // NSLocale(localeIdentifier: "en_US_POSIX")
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZZZZZ"
dateFormatter.date(from: String(describing: unixTimestamp))
let updatedTimeStamp = unixTimestamp
let cellDate = DateFormatter.localizedString(from: updatedTimeStamp as Date, dateStyle: DateFormatter.Style.full, timeStyle: DateFormatter.Style.medium)
cell.subtitleLabel.text = cellDate
}
The result came from this code here:
let myTimeStamp = self.datePicker?.date.timeIntervalSince1970
let calendarDate = String(describing: myTimeStamp! /** 1000*/)

Answer 1

You can convert unixTimestamp to date using Date(timeIntervalSince1970:).
let unixTimestamp = 1480134638.0
let date = Date(timeIntervalSince1970: unixTimestamp)
If you want to display date in string with specific formate than you can use DateFormatter like this way.
let date = Date(timeIntervalSince1970: unixtimeInterval)
let dateFormatter = DateFormatter()
dateFormatter.timeZone = TimeZone(abbreviation: "GMT") //Set timezone that you want
dateFormatter.locale = NSLocale.current
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm" //Specify your format that you want
let strDate = dateFormatter.string(from: date)

Answer 2

The problem is the line dateFormatter.timeZone = NSTimeZone() as TimeZone!.
Simply use TimeZone instead of NSTimeZone like
dateFormatter.timeZone = TimeZone.current and your code will work.
You might also remove your / 1000 because 1480134638.0 looks more like seconds than milliseconds (since 1970).

Answer 3

Swift 4.1. I created a function. Just pass you timeStamp in function param and function will return data in string data type. You can add more properties to DateFormatter object.
func getDateFromTimeStamp(timeStamp : Double) -> String {
let date = NSDate(timeIntervalSince1970: timeStamp / 1000)
let dayTimePeriodFormatter = DateFormatter()
dayTimePeriodFormatter.dateFormat = "dd MMM YY, hh:mm a"
// UnComment below to get only time
// dayTimePeriodFormatter.dateFormat = "hh:mm a"
let dateString = dayTimePeriodFormatter.string(from: date as Date)
return dateString
}

Answer 4

Using playground all I did was this.
let epochTime = 1547855446
let newTime = Date(timeIntervalSince1970: TimeInterval(epochTime))
print(newTime)
Returns this - 2019-01-18 23:50:46 +0000

Answer 5

extension Double{
func convertDate(formate: String) -> String {
let date = (timeIntervalSince1970: self)
let dateFormatter = DateFormatter()
dateFormatter.timeZone = TimeZone.current
dateFormatter.locale = NSLocale(localeIdentifier: "(your localization language)" ) as Locale //localization language
dateFormatter.dateFormat = formate //Specify your format that you want let
strDate = dateFormatter.string(from: date)
return strDate
}
}
//usage
let timeStamp:Double = Double(1595407043)
print(timeStamp.convertDate(formate: "EEEE dd/MM/YYY"))

Answer 6

This solution is valid for swift 3 -> 4.2 :
you can add an extension on the Double that returns the date formatted:
extension Double {
// returns the date formatted.
var dateFormatted : String? {
let date = Date(timeIntervalSince1970: self)
let dateFormatter = DateFormatter()
dateFormatter.timeStyle = DateFormatter.Style.none //Set time style
dateFormatter.dateStyle = DateFormatter.Style.short //Set date style
return dateFormatter.string(from: date)
}
// returns the date formatted according to the format string provided.
func dateFormatted(withFormat format : String) -> String{
let date = Date(timeIntervalSince1970: self)
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = format
return dateFormatter.string(from: date)
}
}
example on the above :
let timeStamp = 82749029.0
print(timeStamp. dateFormatted)
//output
//12/11/1994
let timeStamp = 82749029.0
print(timeStamp. dateFormatted(withFormat : "MM-dd-yyyy HH:mm"))
//output
//12-11-1994 13:04