Find exact difference between two dates

Question

I want some changes in the date comparison.

In my application I am comparing two dates and getting difference as number of Days, but if there is only one day difference

Answer 1

Here a prefect solution to find difference between two dates

- (NSString *)calculateDuration:(NSDate *)oldTime secondDate:(NSDate *)currentTime
{
    NSString *timeSincePost;
 NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
    NSCalendarUnit unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit;
    NSDateComponents *dateComponents = [calendar components:unitFlags fromDate:oldTime toDate:currentTime options:0];

    NSInteger year = [dateComponents year];
    NSInteger month = [dateComponents month];
    NSInteger day = [dateComponents day];
    NSInteger hour = [dateComponents hour];
    NSInteger minute = [dateComponents minute];
    NSInteger second = [dateComponents second];

    if (year) {
        timeSincePost = [NSString stringWithFormat:@"%ld%@", (long)year,[[kAppDelegate languageBundle] localizedStringForKey:@"y" value:@"" table:nil]];
    }
    else if (month) {
         timeSincePost = [NSString stringWithFormat:@"%ld%@", (long)month,[[kAppDelegate languageBundle] localizedStringForKey:@"M" value:@"" table:nil]];
    }
    if(day) {
        timeSincePost = [NSString stringWithFormat:@"%ld%@", (long)day,[[kAppDelegate languageBundle] localizedStringForKey:@"d" value:@"" table:nil]];
    }
    else if(hour) {
        timeSincePost = [NSString stringWithFormat: @"%ld%@", (long)hour,[[kAppDelegate languageBundle] localizedStringForKey:@"H" value:@"" table:nil]];
    }
    else if(minute) {
        timeSincePost = [NSString stringWithFormat: @"%ld%@", (long)minute,[[kAppDelegate languageBundle] localizedStringForKey:@"m" value:@"" table:nil]];
    }
    else if(second)
        timeSincePost = [NSString stringWithFormat: @"%ld%@", (long)second,[[kAppDelegate languageBundle] localizedStringForKey:@"s" value:@"" table:nil]];

    return timeSincePost;
}

and call above function with two parameter as NSDate

NSString *duration = [self calculateDuration:postDate secondDate:[NSDate date]];
lblPostTime.text = duration;

note:: postDate is FirstDate & second date is current date..