Assume I'm given an input string like "7:00". I know that the time is EST but I want to convert it to localized time (so for people in PST it says 4:00). I tried the following code, but I keep getting a 24-hour time from it and the complete date (e.g: Optional(2000-01-01 16:00:00 +0000)). I want just the hour:min time...what am I doing wrong?
var dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "HH:mm"
dateFormatter.timeZone = NSTimeZone.localTimeZone()
gameClock = "\(dateFormatter.dateFromString("7:30"))"
println(gameClock)
You need to specify the time zone for your date formatter that you use to process the server date. By default, the time zone of the date formatter is the default time zone of the device.
So, for your above code, you should do this:
let dateStringFromServer = "07:00"
let serverDateFormatter = NSDateFormatter()
serverDateFormatter.dateFormat = "HH:mm"
serverDateFormatter.timeZone = NSTimeZone(name: "EST")
let dateFromServer = serverDateFormatter.dateFromString(dateStringFromServer)
let localDateFormatter = NSDateFormatter()
serverDateFormatter.dateFormat = "HH:mm"
let localizedStringForThatDate = localDateFormatter.stringFromDate(dateFromServer!)
The dateFormatter.dateFromString("7:30") gives you an NSDate not an NSString. You have make use of another NSDateFormatter object to get the date in desired string format.
let dateFormatterForDisplay = NSDateFormatter();
dateFormatterForDisplay.dateFormat = "HH:mm"
dateFormatterForDisplay.locale = NSLocale(localeIdentifier: "en_US_POSIX")
(you need the last line in the above if you want to force 12 hour mode, the default is NSLocale.currentLocale() and can be 12 hr or 24 hr mode for different locales)
Then
let displayString = dateFormatterForDisplay.stringFromDate(gameClock)
Related
I'm getting this UTC time in string format from the server.."2019-12-18T10:58:40Z"
Now I want to convert it into local time. For that I referred this link. But it's not working..
What I wanted to achieve was to convert UTC time to local time and set a timer based on that time.
This is what I've tried..
var utcTime = "\(json["expirationDate"]!)"
self.dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"
let date = self.dateFormatter.date(from: utcTime)
let utcDate = date?.toGlobalTime()
let localDate = utcDate?.toLocalTime()
But I'm getting nil values for the dates..
You don't have milliseconds in your UTC date string example. Your date format should be
self.dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss'Z'"
you have to change this format from
"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'" to "yyyy-MM-dd'T'HH:mm:ss'Z'"**you have to
let utcTime = "2019-12-18T10:58:40Z"
let dateFormatter = DateFormatter.init()
dateFormatter.timeZone = TimeZone(abbreviation: "UTC")!
dateFormatter.locale = Locale(identifier: "en_US_POSIX")
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss'Z'"
let date = dateFormatter.date(from: utcTime)
print(date)
so here is the string Date that I want to Convert
2019-03-22T00:00:00
and here is the problem
Remember that I used "yyyy-MM-dd'T'HH:mm:ss" or "yyyy-MM-ddTHH:mm:ss" or "yyyy-MM-dd HH:mm:ss" or yyyy-MM-dd'T'HH:mm:ssZ and some other similar formats
You have to set a time zone and locale when parsing internet dates:
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
// necessary to avoid daylight saving (and other time shift) problems
dateFormatter.timeZone = TimeZone(secondsFromGMT: TimeZone.current.secondsFromGMT())
// necessary to avoid problems with 12h vs 24h time formatting
dateFormatter.locale = Locale(identifier: "en_US_POSIX")
print(dateFormatter.date(from: "2019-03-22T00:00:00"))
The default time zone contains information about daylight saving time and some specific times does not exist there. Instead, we have to use a generic time zone.
See https://developer.apple.com/library/archive/qa/qa1480/_index.html
22 March 2019 around midnight is the day & time when daylight saving change in Iran makes an hour non-existent.
The same can be achieved using ISO8601DateFormatter:
let dateFormatter = ISO8601DateFormatter()
dateFormatter.formatOptions = ISO8601DateFormatter.Options.withInternetDateTime.subtracting(.withTimeZone)
print(dateFormatter.date(from: "2019-03-22T00:00:00"))
Try this function might help
public func dateFormatter(strDate: String) -> String{
let dateFormatter = DateFormatter()
dateFormatter.locale = Locale(identifier: "fa_IR")
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss"
let date = dateFormatter.date(from: strDate)
let dateString = dateFormatter.string(from: date!)
return dateString
}
dateFormatter.isLenient = true
Ignores missing hours during daylight saving time offset
I have the following string:
let dateString = "2018-04-18T04:54:00-04:00"
I initialize a Date via the ISO8601DateForamtter by doing the following:
let formatter = ISO8601DateFormatter()
let date = formatter.date(from: dateString)
If I print the date, I get the following:
Apr 18, 2018 at 1:54am
The formatter is automatically converting the time into my local time. How can I prevent accounting for my time zone? For example, I want the Date object to show the following instead:
Apr 18, 2018 at 4:54am
With ISO8601, 2018-04-18T04:54:00-04:00 means 2018-04-18 04:54:00 in GMT -4h. To print the time as it is in the original string, you need to create a date formatter with the specific time zone which is -4.
let dateFormatter = DateFormatter()
dateFormatter.timeZone = TimeZone(secondsFromGMT: -4 * 60 * 60)
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
print(dateFormatter.string(from: date))
You will get
2018-04-17 04:54:00
FYI, I'm adding a link for ISO8601
You need to parse the timezone from your date string and use it to set the timezone from your date formatter:
func secondsFromGMT(from string: String) -> Int {
guard !string.hasSuffix("Z") else { return 0 }
let timeZone = string.suffix(6)
let comps = timeZone.components(separatedBy: ":")
guard let hours = comps.first,
let minutes = comps.last,
let hr = Int(hours),
let min = Int(minutes) else { return 0 }
return hr * 3600 + min * 60
}
let dateString = "2018-04-18T04:54:00-04:00"
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssxxxxx"
formatter.locale = Locale(identifier: "en_US_POSIX")
if let dateFromString = formatter.date(from: dateString) {
formatter.timeZone = TimeZone(secondsFromGMT: secondsFromGMT(from: dateString))
formatter.dateFormat = "MMM dd, yyyy 'at' h:mma"
formatter.amSymbol = "am"
formatter.pmSymbol = "pm"
print(formatter.string(from: dateFromString)) // Apr 18, 2018 at 4:54am
}
Instead of logging the Date directly, have a look at the string(from:timeZone:formatOptions:) method on ISO8601DateFormatter. With this, you should be able to get a date string for any time zone you desire.
You should set your formatter to the appropriate timezone such as (UTC example below):
formatter.timeZone = TimeZone(identifier: "UTC")
or alternatively specify against GMT:
formatter.timeZone = TimeZone(secondsFromGMT: 0)
The date that you are receiving from your current formatter is technically correct. Setting the date backwards as described in the currently accepted answer is not advised because you are effectively hard-coding an intended time zone. As soon as your device enters another time zone (or if a user downloads your app outside of the current time zone), your information will be incorrect.
If you are trying to display this time in the UTC time zone, you need to use another formatter to correctly format the output in the target time zone.
let utcFormatter = DateFormatter()
utcFormatter.timeZone = TimeZone(secondsFromGMT: 0)
// Perform any other transformations you'd like
let output = utcFormatter.string(from: date)
But why is your original date correct?
The Date API is incredibly robust and doing a lot of things under-the-hood, but is effectively implemented using a simple Double. The automaic time-zone information that it's displaying to you is an abstraction to make it easier to reason about. A date technically has no knowledge of what time zone it's in – but converting it to a string implicitly applies an inferred date formatter on the date and returns information it thinks will be most useful to you.
If you're doing manipulations on a date, you're likely using the Calendar API. You typically get a new instance from using Calendar.current, which will create a new calendar with your current time zone information. You can change the represented time zone of the calendar like this:
var calendar = Calendar.current
calendar.timeZone = TimeZone(secondsFromGMT: 0)
This will give you relative dates that will work in any time zone without modifying the base Date object that you're working with.
I have displayed the list of timezones in my app. If user selects a particular timezones, I need to change the local timezone to the selected timezone by the user.
let region = Region(tz: timeZoneName.timeZone , cal: cal, loc: cal.locale!)
let date = Date().inRegion(region: region).absoluteDate
Here is the problem, the region is changed to the selected timezone but the date issuing the local timezone.
A Date contains no timezone. From apple's docs: A specific point in time, independent of any calendar or time zone.
The timezone comes into play as soon as you want to present a date to the user. And that's what a DateFormatter is for. As #AlexWoe89 already pointed out, it let's you convert a string, containing a date into a Date object, but also lets you convert a given date into a string representing the date in the time zone you set to the timeZone property of DateFormatter.
let date = Date()
var dateFormatter = DateFormatter()
dateFormatter.locale = Locale(identifier: "en_US_POSIX")
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm"
dateFormatter.timeZone = TimeZone(identifier: "America/Los_Angeles")
let dateString1 = dateFormatter.string(from: date)
dateFormatter.timeZone = TimeZone(identifier: "Germany/Berlin")
let dateString2 = dateFormatter.string(from: date)
This will store 2017-10-23 04:27 in dateString1, while the same date leads to 2017-10-23 13:27 in dateString2.
You can use DateFormatter as a solution, try something like this:
let dateString = "<yourDateAsString>"
let dateFormatter = DateFormatter()
dateFormatter.locale = Locale(identifier: "en_US_POSIX") // => there are a lot of identifiers you can use
dateFormatter.timeZone = TimeZone(secondsFromGMT: 0)
dateFormatter.defaultDate = Date()
dateFormatter.dateFormat = "dd-MM-yyyy hh:mm” // => your needed time format
let convertedDate = dateFormatter.date(from: dateString)
I have a string of text in my application that conveys a time and the date, such as let time = "2017-07-09T09:17:08+00:00". I want to take this string, which is in UTC, and convert it to a string that presents the time in EST. For my example, the resulting string would be 2017-07-09T05:17:08+00:00. How can this be done?
I've tried using
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
dateFormatter.timeZone = TimeZone.current
let date = dateFormatter.date(from:time!)!
but printing the date gives me the same time in UTC.
All you need to do is to use a DateFormatter to convert your Date object into a String. By default, the date will be formatted to local time.
// First, get a Date from the String
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
let date = dateFormatter.date(from:time!)!
// Now, get a new string from the Date in the proper format for the user's locale
dateFormatter.dateFormat = nil
dateFormatter.dateStyle = .long // set as desired
dateFormatter.timeStyle = .medium // set as desired
let local = dateFormatter.string(from: date)
Note that there is no need to set any timezone for either set of code in this case.