Hours in NSDate every time in 24-hour style? - ios

Question

I have this date formatter:
NSDateFormatter *timeFormatter = [[NSDateFormatter alloc] init];
[timeFormatter setDateFormat:#"HH:mm"];
If I use this:
NSDate *myDate = [timeFormatter dateFromString:#"13:00"];
It returns this:
"1:00"
This is because the simulator has switched off 24-hour. But for my app I really need "13:00" instead of "1:00"
--- EDIT 1 ---
Added new code:
NSCalendar *calendar= [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSCalendarUnit unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
NSDateFormatter *timeFormatter = [[NSDateFormatter alloc] init];
[timeFormatter setDateFormat:#"HH:mm"];
NSDate *timeForFirstRow = [timeFormatter dateFromString:#"13:00"];
NSDateComponents *dateComponents = [calendar components:unitFlags fromDate:timeForFirstRow];
NSInteger hour = [dateComponents hour]; //This will be 1 instead of 13
NSInteger minute = [dateComponents minute];

Answer 1

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 2

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"];

Answer 3

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 4

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 5

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