How to calculate how much time passed from the date with timezone? - ios

Question

I get from the server a date with this format:
2016-05-27 17:33:43+0400
Now, I want to detect, how much time passed since that date? For example 1 day 5 hours 10 minutes 20 seconds.
How can I do it? I know how to calculate this from the timestamp, but do not know how to convert this to a timestamp.
Can anyone help me with it?
For example:
Convert this 2016-05-27 17:33:43+0400 to 1464370423 this
Or maybe there are another solution. I just want to calculate how much time passed since that time

Answer 1

You can use NSDateComponents formatter to get the relative time between two dates. Regarding the date string format you need to use xx for the time zone part.
let dateStr = "2016-05-27 17:33:43+0400"
let formatter = NSDateFormatter()
formatter.dateFormat = "yyyy-MM-dd HH:mm:ssxx"
formatter.calendar = NSCalendar(calendarIdentifier: NSCalendarIdentifierISO8601)
formatter.locale = NSLocale(localeIdentifier: "en_US_POSIX")
if let date = formatter.dateFromString(dateStr) {
print(date) // "2016-05-27 13:33:00 +0000\n" -4hs
let dateComponentsFormatter = NSDateComponentsFormatter()
dateComponentsFormatter.allowedUnits = [.Day,.Hour,.Minute,.Second]
dateComponentsFormatter.unitsStyle = .Full
print(dateComponentsFormatter.stringFromDate(date, toDate: NSDate()) ?? "") // 6 days, 17 hours, 51 minutes, 29 seconds
}

Answer 2

given the input string you can convert it to a date and subsequently to an NSTimeInterval since the current time using the following.
let inputDate = "2016-05-27 17:33:43+0400"
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ssZZZZZ"
if let aDate = dateFormatter.dateFromString(inputDate) {
let timeInterval = aDate.timeIntervalSinceNow
let dateComponentsFormatter = NSDateComponentsFormatter()
if let dateString = dateComponentsFormatter.stringFromTimeInterval(abs(timeInterval)) {
print ("Elapsed time=\(dateString)")
}
}
Output:
Elapsed time=6d 17:51:52
You can get the date as the timestamp in your question using aDate.timeIntervalSince1970

Answer 3

I suggest that this could help you: How to get the current time as datetime
You can get the current time and calculate the difference using the server time and your current time.
let date = NSDate()
let calendar = NSCalendar.currentCalendar()
let components = calendar.components(.CalendarUnitHour | .CalendarUnitMinute, fromDate: date)
let hour = components.hour
let minutes = components.minute
Hope it helps.

Answer 4

This will tell you
"how many time"
passed since an event.
let date = Date()
let howManyTimePassed = date.timeIntervalSinceNow
TimeInterval is a typealias for a double, meaning its another way to say double. The value of the timeInterval represents seconds.

Answer 5

Try this class in Swift 5.1:
open class MyDateClass: NSObject {
private var result:MyDateTime!
init(dateStr: String, inputFormat: String) {
let formatter = DateFormatter()
formatter.dateFormat = inputFormat //"yyyy-MM-dd HH:mm:ss"
formatter.calendar = Calendar(identifier: .gregorian)
formatter.locale = Locale(identifier: "en_US_POSIX")
if let date = formatter.date(from: dateStr) {
let dateComponentsFormatter = DateComponentsFormatter()
dateComponentsFormatter.allowedUnits = [.year,.month,.day,.hour,.minute,.second]
dateComponentsFormatter.unitsStyle = .full
let strFromat = dateComponentsFormatter.string(from: date, to: Date()) ?? ""
var trimmedString = strFromat.replacingOccurrences(of: " ", with: "")
trimmedString = trimmedString.replacingOccurrences(of: "years", with: "")
trimmedString = trimmedString.replacingOccurrences(of: "months", with: "")
trimmedString = trimmedString.replacingOccurrences(of: "days", with: "")
trimmedString = trimmedString.replacingOccurrences(of: "hours", with: "")
trimmedString = trimmedString.replacingOccurrences(of: "minutes", with: "")
trimmedString = trimmedString.replacingOccurrences(of: "seconds", with: "")
let arr = trimmedString.split(separator: ",")
let result = MyDateTime(year: Int(arr[0]), month: Int(arr[1]), day: Int(arr[2]), hour: Int(arr[3]), minute: Int(arr[4]), second: Int(arr[5]))
self.result = result
}
}
func getDateTime() -> MyDateTime {
return result
}
}
public struct MyDateTime {
var year:Int?
var month:Int?
var day:Int?
var hour:Int?
var minute:Int?
var second:Int?
}
And this class works like this:
let myClass = MyDateClass(dateStr: "2016-05-27 17:33:43", inputFormat: "yyyy-MM-dd HH:mm:ss")
let time = myClass.getDateTime()
Now you can show time as you wish.