Find if user prefers 12 / 24 Hour Clock?

Question

I've got a drawRect that makes a timeline a bit like iCal. I use a for loop to write the times along a scroll view. I was wondering if A) theres a way of determining whether the user has chosen a 12 or 24 hour clock in the system settings and B) if there is a more efficient way of changing the time labels then calling an 'if' query every pass of the 'for' loop. Cheers

Answer 1

The earlier answers assume that the "AM" and "PM" symbols are represented in roman characters. This code adapted from keyur bhalodiya does a better job at handling languages like Chinese, by using the AMSymbol and PMSymbol methods of NSDateFormatter.

-(BOOL)uses24hourTime
{
     NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
     [formatter setLocale:[NSLocale currentLocale]];
     [formatter setDateStyle:NSDateFormatterNoStyle];
     [formatter setTimeStyle:NSDateFormatterShortStyle];

     NSString *dateString = [formatter stringFromDate:[NSDate date]];
     NSRange amRange = [dateString rangeOfString:[formatter AMSymbol]];
     NSRange pmRange = [dateString rangeOfString:[formatter PMSymbol]];

     return (amRange.location == NSNotFound && pmRange.location == NSNotFound);
}