How can I calculate the difference between two dates?

Question

How can I calculate the days between 1 Jan 2010 and (for example) 3 Feb 2010?

Answer 1

If you want all the units, not just the biggest one, use one of these 2 methods (based on @Ankish's answer):

Example output: 28 D | 23 H | 59 M | 59 S

+ (NSString *) remaningTime:(NSDate *)startDate endDate:(NSDate *)endDate
{
    NSCalendarUnit units = NSCalendarUnitDay | NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond;
    NSDateComponents *components = [[NSCalendar currentCalendar] components:units fromDate: startDate toDate: endDate options: 0];
    return [NSString stringWithFormat:@"%ti D | %ti H | %ti M | %ti S", [components day], [components hour], [components minute], [components second]];
}

+ (NSString *) timeFromNowUntil:(NSDate *)endDate
{
    return [self remaningTime:[NSDate date] endDate:endDate];
}