iOS - how to compare two times?

Question

I use the following function to check if a message has expired -

- (BOOL) hasExpired:(NSDate*)myDate
{     
    if(myDate == nil)
    {
        return false;
    }
    NSDate *now = [NSDate date];
    return !([now compare:myDate] == NSOrderedAscending);
}

This works fine if I am comparing two different dates. However, it returns false if the message has expired earlier in the day today. Any ideas on how I might fix it?

This should not happen, also 1 second difference between NSDate instances is enough. Add an `NSLog()` with both dates there to see whether they are indeed different. — Pascal, Dec 21 '11 at 20:12
You were right. If you turn it into an answer I could accept it. — Suchi, Jan 03 '12 at 17:22

score 2 · Answer 1 · answered Dec 21 '11 at 20:49

You can use system method of NSDate class to compare with current time

- (NSTimeInterval)timeIntervalSinceNow

Return value is the interval between the receiver and the current date and time. If the receiver is earlier than the current date and time, the return value is negative.

So correct code will be

- (BOOL) hasExpired:(NSDate*)myDate 
{
    return [myDate timeIntervalSinceNow] < 0.f;
}

Or if you want to compare 2 dates, use

- (NSTimeInterval)timeIntervalSinceDate:(NSDate *)anotherDate

score 2 · Accepted Answer · answered Jan 05 '12 at 18:17

2

(Adding my comment as an answer:)

This should not happen, also 1 second difference between NSDate instances is enough. Add an NSLog() with both dates there to see whether they are different indeed.

answered Jan 05 '12 at 18:17

Pascal

16,846
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score 1 · Answer 3 · edited Apr 14 '16 at 14:29

1

+(BOOL)isEndDateBigger :(NSDate *)currDate :(NSDate *)endDate {
     if ([currDate compare:endDate] == NSOrderedDescending) {
     NSLog(@"date1 is later than date2");
     return YES; 
     } else if ([currDate compare:endDate] == NSOrderedAscending) {
     return NO;
     } else {
     return NO;
   }
}

edited Apr 14 '16 at 14:29

Gajendra K Chauhan

3,387
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answered Jul 24 '14 at 09:05

Nits007ak

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bweberapps · Answer 4 · 2011-12-21T20:14:01.177

0

Check to see if it is returning NSOrderedSame when it is the same day. Maybe you need to compare the time as well, separately.

edited Dec 21 '11 at 20:14

answered Dec 21 '11 at 20:08

bweberapps

86
3

iOS - how to compare two times?

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