localization - Detect whether iPhone is displaying time in 12-Hour or 24-Hour Mode?

Question

How can you detect whether iPhone is displaying time in 12-Hour or 24-Hour Mode?

I currently monitor the current region for changes, however that's not the only setting that affects how times are displayed. The 24-hour toggle in the date & time settings overrides the current regions settings.

Is there any way to detect this 12/14 hour setting?

Answer 1

I've figured out a decent way of determining this with a little function I've added to a category of NSLocale. It appears to be pretty accurate and haven't found any problems with it while testing with several regions.

@implementation NSLocale (Misc)
- (BOOL)timeIs24HourFormat {
    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateStyle:NSDateFormatterNoStyle];
    [formatter setTimeStyle:NSDateFormatterShortStyle];
    NSString *dateString = [formatter stringFromDate:[NSDate date]];
    NSRange amRange = [dateString rangeOfString:[formatter AMSymbol]];
    NSRange pmRange = [dateString rangeOfString:[formatter PMSymbol]];
    BOOL is24Hour = amRange.location == NSNotFound && pmRange.location == NSNotFound;
    [formatter release];
    return is24Hour;
}
@end