swift_There is a problem of several hours difference when transferring the time obtained by UIDatePicker to the next page_html/css_WEB-ITnose

Today, I encountered a very strange problem when writing a swift demo. I used UIDatePicker to select the time on the presented page, and then transferred the obtained time back to the original main interface. The result was a problem Appears: The acquisition time of page B is normal, but the time after page A is returned is 9 hours less. I was puzzled, so I found some answers on Google and said it was like this:

 time.timeZone = NSTimeZone.systemTimeZone() time.calendar = NSCalendar(calendarIdentifier: NSGregorianCalendar)

Even after adding it, it had no effect, and the difference was still the same 9 hours. Later, I found another solution like this:

let timeZone = NSTimeZone.systemTimeZone()let seconds = timeZone.secondsFromGMTForDate(addObject.time.date)let correctDate = addObject.time.date.dateByAddingTimeInterval(Double(seconds))

Although the problem was solved, I still don’t understand why. Could this be the reason for the XCode GM version (unlikely~). I hope those who know the reason will give me some advice and we can make progress together!