Compare three dates

Question

I have three dates 'startDate', stopDate and currentDate. I need compare 'startDate' <= 'currentDate' and 'stopDate' >= 'currentDate'. My code.

unsigned int flagsDate = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit;

    NSDateComponents* fromComponents = [[NSCalendar currentCalendar] components:flagsDate fromDate:startDate];
    NSDate* fromDateOnly = [[NSCalendar currentCalendar] dateFromComponents:fromComponents];

    NSDateComponents* toComponents = [[NSCalendar currentCalendar] components:flagsDate fromDate:stopDate];
    NSDate* toDateOnly = [[NSCalendar currentCalendar] dateFromComponents:toComponents];

    NSDate * currentDate = [NSDate date];
    NSDateComponents* currComponents = [[NSCalendar currentCalendar] components:flagsDate fromDate: currentDate];
    NSDate* currDateOnly = [[NSCalendar currentCalendar] dateFromComponents:currComponents];

    NSTimeInterval fromTime = [fromDateOnly timeIntervalSinceReferenceDate];
    NSTimeInterval toTime = [toDateOnly timeIntervalSinceReferenceDate];
    NSTimeInterval currTime = [currDateOnly timeIntervalSinceReferenceDate];

    NSLog(@"%@ %@",currentDate, currDateOnly);
    NSLog(@"%@ %@",startDate, fromDateOnly);
    NSLog(@"%@ %@",stopDate, toDateOnly);

That's what brings nslog.

2014-04-10 23:59:53.280 Calendar[2148:90b] 2014-04-10 19:59:53 +0000 2014-04-09 20:00:00 +0000 2014-04-10 23:59:53.282 Calendar[2148:90b] 2014-04-10 20:14:12 +0000 2014-04-10 20:00:00 +0000 2014-04-10 23:59:53.282 Calendar[2148:90b] 2015-04-09 20:14:12 +0000 2015-04-09 20:00:00 +0000

How do I compare dates? I need to compare dates only without time. Why change the date if time is less than 20:00?

Answer 1

NSTimeInterval distanceBetweenDates = [StartDate timeIntervalSinceDate:EndDate];

if (distanceBetweenDates > 0) {
    NSLog("Greather than ")
} else  if (distanceBetweenDates < 0) {
    NSLog("less than");
} else {
    NSLog("Equal");
}

Answer 2

Alexey, I suggest you incorporate this wonderful NSDate extension in your project: https://github.com/erica/NSDate-Extensions

You can then use

- (NSInteger)distanceInDaysToDate:(NSDate *)anotherDate

And check if it's < 0, 0 or > 0

Answer 3

If you wanted to compare only the dates, do as follows:

NSInteger flagsDate = (NSDayCalendarUnit | NSMonthCalendarUnit | NSYearCalendarUnit);

NSDateComponents* fromComponents = [[NSCalendar currentCalendar] components:flagsDate fromDate:startDate];
NSDateComponents* toComponents = [[NSCalendar currentCalendar] components:flagsDate fromDate:stopDate];
NSDateComponents* currComponents = [[NSCalendar currentCalendar] components:flagsDate fromDate:cu];

NSComparisonResult firstComparison = [[fromComponents date] compare: [currComponents date]]; 
NSComparisonResult secondComparison = [[toComponents date] compare: [currComponents date]]; 

then to check your result

if (firstComparison == NSOrderedDescending || firstComparison == NSOrderedSame) {}
if (secondComparison == NSOrderedSame || secondComparison == NSOrderedAscending) {}