NSDateFormatter dateFromString and iPhone in 24 Hour Format Confusion

NSDate* date = [NSDate date];

    NSLog(@"datad %@",date)

    NSDateFormatter* formatter = [[[NSDateFormatter alloc] init] autorelease];

    NSLocale   *enUSPOSIXLocale = [[[NSLocale alloc] initWithLocaleIdentifier:@"en_US_POSIX"] autorelease];

    [formatter setLocale:enUSPOSIXLocale];

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

    NSString* str = [formatter stringFromDate:date];

    NSLog(@"str %@",str);