How to check if 2 Dates have a difference of 30days?

Question

Possible Duplicate:
How can I calculate the difference between two dates?
NSDate, comparing two dates

I have got two dates. How to check if theres a difference of 30 days in between them? I actually have an In-App purchase which needs to be disabled after every 30-days of purchase. When the user buys the feature, the Date is saved and so I need to check the dates. If 30-days have passed, I need to disable the feature again.

Please learn to use the search function on Stack Overflow. This question has been asked many many times before. — Nick Bull, Jul 12 '12 at 11:48
possible duplicate of [How can I calculate the difference between two dates?](http://stackoverflow.com/questions/4371757/how-can-i-calculate-the-difference-between-two-dates), [Number of days between two NSDates](http://stackoverflow.com/questions/4739483/number-of-days-between-two-nsdates) — jscs, Jul 12 '12 at 16:49

Michal · Accepted Answer · 2012-07-12T12:06:41.267

6

You can convert both dates to seconds with timeIntervalSince1970 and then check if difference is bigger than 2592000 (30*24*60*60 which is 30 days * 24 hours * 60 minutes * 60 seconds).

NSTimeInterval difference = [date1 timeIntervalSince1970] - [date2 timeIntervalSince1970];

if(difference >2592000)
{
 //do your stuff here
}

EDIT: For more compact version you can use - (NSTimeInterval)timeIntervalSinceDate:(NSDate *)anotherDate

NSTimeInterval difference = [date1 timeIntervalSinceDate:date2];
if(difference >2592000)
{
    //do your stuff here
}

edited Jul 12 '12 at 12:06

answered Jul 12 '12 at 11:46

Michal

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this will fail for DST times. – vikingosegundo Jul 13 '16 at 18:15
@vikingosegundo really? why would that fail? – Michal Jul 14 '16 at 13:48
because not every day has 24 hours. In regions with DST one day has 23, one 25. – vikingosegundo Jul 14 '16 at 14:01
@vikingosegundo yes, that's true, user might get 2 hours less or more of subscription. – Michal Oct 25 '19 at 09:31
You thought 39 month about this? Wow, you are a thorough thinker. – vikingosegundo Oct 25 '19 at 09:48

score 1 · Answer 2 · answered Jul 12 '12 at 12:51

Provide the start and end NSDate in following manner:

    NSDate *date_Start;
    NSDate *date_End;
    NSCalendar *cal=[NSCalendar currentCalendar];
NSDateComponents *components=[cal components:NSDayCalendarUnit fromDate:date_Start toDate:date_End options:0];
    int days=[components day];
    if(days>30){
     //Your code here
    }

score -1 · Answer 3 · answered Jul 12 '12 at 11:45

-1

You could create a date which is +30days from now :

NSDate *thrityDaysPlus = [[NSDate date] dateByAddingTimeInterval:3600*24*30]

and then simply compare it to your saved date

if ([date1 compare:date2] == NSOrderedDescending) {
    NSLog(@"date1 is later than date2");        

} else if ([date1 compare:date2] == NSOrderedAscending) {
    NSLog(@"date1 is earlier than date2");

} else {
    NSLog(@"dates are the same");

}

answered Jul 12 '12 at 11:45

Alexander

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will fail when it comes to DST – vikingosegundo Jul 13 '16 at 18:15

How to check if 2 Dates have a difference of 30days?

3 Answers3