Swift 3.0 Converting String to Date - swift

Question

I'm trying to convert String date to local timeZone date then convert it back to Date with my current timeZone first method is working well:
let date = convertToLocalTimeZone(dateStr:"2018-05-30T14:13:20.000Z")
print(date)
the following is printed which is right:
2018-05-30 16:13GMT+2
let newDate = convertStringToDate(dateStr:date)
print(newDate)
//Converted back to UTC Time Zone :(
2018-05-30 14:13:00 +0000
func convertToLocalTimeZone(dateStr:String)->String{
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:sss.SSSZ"
dateFormatter.timeZone = TimeZone(abbreviation: "UTC")
let date = dateFormatter.date (from: dateStr)
dateFormatter.timeZone = TimeZone(secondsFromGMT: getSecondsFromGMT())
dateFormatter.dateFormat = "yyyy-MM-dd HH:mmz"
let strVal = dateFormatter.string(from: date!)
return strVal
}
The problem happens when i try to convert the new String date with my local timeZone to date it returns wrong timeZone:
func convertStringToDate(dateStr:String)->Date{
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd HH:mmz"
// dateFormatter.timeZone = TimeZone(abbreviation: "GMT+2")
let date = dateFormatter.date (from: dateStr)
let calendar = Calendar.current
let components = calendar.dateComponents([.year, .month, .day, .hour], from: date!)
let finalDate = calendar.date(from:components)
return finalDate!
}
Any Help will be much appreciated

Answer 1

I think your code is alright. You just have to understand that Date represents a point in time. It does not know anything about time zones. Time zones appears only when you format the date, so only in a String will you ever see a time zone. No matter how you create a Date, you are going to see it end up in UTC when it is printed directly.
So if you want to show a date in a time zone, format it, just like you did in convertToLocalTimeZone.
If you want, you could create your own date with a Date and a TimeZone:
struct ZonedDate: CustomStringConvertible {
var date: Date
var timeZone: TimeZone
var description: String {
// format the date using timeZone here...
}
}