Question

The Unicode Date Format Patterns guide (here) state that appending an ‘a’ to the format will get the period (AM or PM for instance), e.g.,

[formatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss a"];

However I wish to ensure that the period information does not appear but I cannot find a format string to do that. The format string I am using is as follows:

[formatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss"];

unfortunately, when I use stringFromDate I get the following:

2013-01-09T11:11:00 AM

I dont wish to simply strip AM or PM from the resultant string because the period syntax may be different in differing Calendars etc, I just want to stop the period information appearing.

—-8<——

Consider the following code

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setLocale:[NSLocale currentLocale]];
[formatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"UTC"]];
[formatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss"];
NSString *stringDate = [formatter stringFromDate:[NSDate date]];

self.labelOutput.text = stringDate;

[formatter release];

This code will produce a string in the format I want – however I cannot use it for memory management reasons. The app I am working on is plagued by NSDateFormatter memory leaks. So we use a singleton class to provide a set number NSDateFormatters to the app which are never released and therefore we minimise how much memory is being leaked. Unfortunately these static NSDateFormatters are appending AM / PM even when I apply a date format string thus:

NSDateFormatter *formatter = [MyDateFormatter dateFormat:kFormatDateMediumStyleTimeShortStyle];

[formatter setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"UTC"]];
[formatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss"];

Answer 1

Here is the answer I have settled on. It’s a bit simplistic but it does the job.

@interface NSDateFormatter (Utils)

- (NSString *)stringWithNoPeriodInformationFromDate:(NSDate*)date;

@end

@implementation NSDateFormatter (Utils)

- (NSString *)stringWithNoPeriodInformationFromDate:(NSDate*)date
{
    NSString *stringWithPotentialPeriodInformation = [self stringFromDate:date];
    NSString *stringWithNoAMInformation = [stringWithPotentialPeriodInformation stringByReplacingOccurrencesOfString:[self AMSymbol] withString:@""];
    NSString *stringWithNoPeriodInformation = [stringWithNoAMInformation stringByReplacingOccurrencesOfString:[self PMSymbol] withString:@""];

    return stringWithNoPeriodInformation;
}

@end