Hours in NSDate every time in 24-hour style?

Question

I have this date formatter:

 NSDateFormatter *timeFormatter = [[NSDateFormatter alloc] init];
 [timeFormatter setDateFormat:@\"HH:mm\"];

If I u

Answer 1

You have to two steps here

NSLocale* locale = [[NSLocale alloc] initWithLocaleIdentifier:@"en_GB"];
[formatter setLocale:locale];

[formatter setDateFormat:@"hh:mm a"];

here a in the formatter gives am/pm format

Answer 2

From Apple Documentation, the time formatting strings follow Unicode Technical Standard #35.

As stated in UTR #35, uppercase HH gives you 24-hour style time while lowercase hh gives you 12-hour style time.

In short, if you need 24-hour style, use [timeFormatter setDateFormat:@"HH:mm"]; and if you need 12-hour style, use [timeFormatter setDateFormat:@"hh:mm"];

Answer 3

If you want to force it to 12-hour or 24-hour mode, regardless of the user's 24/12 hour mode setting, you should set the locale of the date formatter to en_US_POSIX (for 12-hour), or, say, en_GB for the 24-hour mode.

That is,

NSLocale* formatterLocale = [[[NSLocale alloc] initWithLocaleIdentifier:@"en_GB"] autorelease];
[timeFormatter setLocale:formatterLocale];

Some more on that here:

http://developer.apple.com/iphone/library/qa/qa2010/qa1480.html

Answer 4

If it helps anyone I have just had an issue where I want to display the time for the user in the way they have set on their device:

let timeFormatter = NSDateFormatter()
timeFormatter.timeStyle = NSDateFormatterStyle.ShortStyle
//get the time from the picker

The send the time to our API in 24 style:

timeFormatter.locale = NSLocale(localeIdentifier: "en_GB")
//get the time again

Answer 5

I had this same issue recently and came across this document which lists all the date format patterns: http://unicode.org/reports/tr35/tr35-6.html#Date_Format_Patterns

I was able to get 24-times working just by using k:mm as the date format:

NSDateFormatter *format = [[NSDateFormatter alloc] init];
[format setDateFormat:@"k:mm"];