bymafmaf bymafmaf - 4 months ago 103
iOS Question

Swift 3 DateFormatter doesn't return date for "HH:mm:ss"

Here is the code excerpt:

func mapping(map: Map) {
time <- (map["time"], TransformOf<Date, String>(fromJSON: {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "HH:mm:ss"
//dateFormatter.timeZone = TimeZone(abbreviation: "EEST")
if let argument = $0 {
let date = argument)
return argument)
return nil

is string with
. I put "let date" to see what it returns and it's nil. I've looked up for format codes here:

Code should work actually. What am I doing wrong?

EDIT: Added the whole function

EDIT2: I just noticed it's working properly on iPhone 7 iOS 10.1 simulator but returns nil on my iPod 10.1.1 (2016). This is so weird.


From Technical Q&A QA1480 – NSDateFormatter and Internet Dates:

On the other hand, if you're working with fixed-format dates, you should first set the locale of the date formatter to something appropriate for your fixed format. In most cases the best locale to choose is "en_US_POSIX", a locale that's specifically designed to yield US English results regardless of both user and system preferences.

This will prevent the date from being interpreted according to the user's regional settings:

let dateFormatter = DateFormatter()
formatter.locale = Locale(identifier: "en_US_POSIX")
dateFormatter.dateFormat = "HH:mm:ss"
// ...

See also What is the best way to deal with the NSDateFormatter locale "feature"?.