iOS: Compare two less or equal NSDates

Question

I want to compare two dates and do something when one is less or equal than the other, I tried to do it this way:

if ([self.system.systemInbetriebnahme compare:date] == NSOrderedDescending)
        return nil;

But this removes the case when they are both equal is there a way to compare dates with >= ?

Thank you

More details: I have a date taken from a double dimension array, and i have a date stored in core data(through date picker), and i go through a loop to compare the two dates with the rule that: Date in array must be greater or equal than input date stored in database.

Latest Edit:

I import a csv file which after parsing and formatting gives me two rows(one for number value and one for dates). Here I am interested in dates.

I store all these in an array and save after checking consistency of the data in this function:

for (NSArray * row in array) {


 // Handle import if there are at least two rows


if (row.count > 1) {

            dispatch_sync(dispatch_get_main_queue(), ^{
                // Try to import value,date formatted row
                double value = [row[0] doubleValue];
                NSDate * date = [dateFormatter dateFromString:row[1]];
               //else {

                    // Try to import date,value row

                    if (date && value != 0.0) {
                        [self addReading:value forDate:date];
                    }

In here i call the function addreading to check for errors for some rules and if everything is okey then i save the managedObject Context.

 if ([installationdatum compare:date] != NSOrderedAscending)
               { 
               UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil
                 message:@"installation date is bigger than data"
                                                                  delegate: nil
                                                         cancelButtonTitle:@"OK"
                                                         otherButtonTitles:nil] 

                    [alert show];
                   return nil;



               } else
               {  //Do nothing

               }

One rule for me is to get the first row element in the array and compare its date with an input stored already in the database which is the self.system.systemInbetriebnahme
After all this I list all the resulting array in a tableview, though value matching NSOrderedSame is never shown when it is equal to self.system.systemInbetriebnahme

You could get thousands of link for the same, why dont you search SO before posting the ques? — Sahil Mittal, Aug 27 '13 at 12:46
because it does not answer the question about date comparison simulating operator >=. — Souhail Marghabi, Aug 27 '13 at 12:57

score 12 · Answer 1 · answered Aug 27 '13 at 12:34

12

Simple...

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 Aug 27 '13 at 12:34

Kumar KL

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1

Copy&pasted from [the answer of a different person](http://stackoverflow.com/a/5965106/400056) without attribution. Please do not do that. – DarkDust Feb 18 '15 at 15:27
@DarkDust: Yes it was copied to my code(project) before this question, Later I searched for the link, I didn't get so . I copied from my code n added here. – Kumar KL Feb 19 '15 at 04:30

score 11 · Accepted Answer · answered Aug 27 '13 at 12:34

11

Simply check for not ascending order.

if ([self.system.systemInbetriebnahme compare:date] != NSOrderedAscending)
        return nil;

answered Aug 27 '13 at 12:34

Mike Kwan

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what does not ascending order imply in logical expression? – Souhail Marghabi Aug 27 '13 at 12:43
3

It implies either `NSOrderedDescending` or `NSOrderedSame` – Gabriele Petronella Aug 27 '13 at 12:46
There are only three valid values for the enum - `NSOrderedAscending`, `NSOrderedDescending` or `NSOrderedSame`. So not being ascending means it is same or descending. – Mike Kwan Aug 27 '13 at 12:57
I understand, I tried but it still ignores the value at NSOrderedSame. I dont know why – Souhail Marghabi Aug 27 '13 at 12:58
Can you elaborate? What do you mean by ignore? Are you sure the two dates are absolutely the same? – Gabriele Petronella Aug 27 '13 at 13:04
I have a date taken from a double dimension array, and i have a date stored in core data(through date picker), and i go through a loop to compare the two dates with the rule that: Date in array must be greater or equal than input date stored in database. – Souhail Marghabi Aug 27 '13 at 13:13
Can you edit your question with more code and details? – Mike Kwan Aug 27 '13 at 13:42
okey will do, please recheck – Souhail Marghabi Aug 27 '13 at 14:40

Bug · Answer 3 · 2013-08-29T18:07:30.437

3

NSDate *toDay = [[NSDate alloc]init];

NSLog(@"%@",toDay);

 NSLog(@"%@",yourSecondDate);

if ([toDay timeIntervalSinceDate:yourSecondDate] < 30.0f) 
 {
    NSLog(@"Do Something");
 }

edited Aug 29 '13 at 18:07

answered Aug 27 '13 at 12:35

Bug

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Thanks. Time interval worked well for my scenario. – Mark.ewd Dec 16 '14 at 15:39

score 1 · Answer 4 · answered Aug 27 '13 at 12:35

1

Well >= just means that they are !<, so you can check

if ([self.system.systemInbetriebnahme compare:date] != NSOrderedAscending)

answered Aug 27 '13 at 12:35

Levi

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what you wrote implies : == NSOrderedDescending, which does not account when both dates can be equal. – Souhail Marghabi Aug 27 '13 at 12:40
1

It doesn't imply that. You're missing the third case, `NSOrderedSame`. This answer does what you want – Gabriele Petronella Aug 27 '13 at 12:46
I thought it would but, it still does not take into account the case when NSOrderedSame is true :( – Souhail Marghabi Aug 27 '13 at 12:55
1

Yes it does. If it is NOT NSOrderedAscending, then it is either NSOrderedDescending or NSOrderedSame, just like @Gabriele said – Levi Aug 27 '13 at 13:01

rckoenes · Answer 5 · 2013-08-27T13:48:40.147

You could either check if the result is equal to both NSOrderedDescending and NSOrderedSame:

NSComparisonResult comparisonResult = [self.system.systemInbetriebnahme compare:date]
if (comparisonResult == NSOrderedDescending  || comparisonResult == NSOrderedSame)
        return nil;

Or just not match the one option left:

NSComparisonResult comparisonResult = [self.system.systemInbetriebnahme compare:date]
if (comparisonResult != NSOrderedAscending)
        return nil;

In your case I would go the later option, since you only have 3 options check against the one you don't want is easiest.

score 0 · Answer 6 · answered Aug 27 '13 at 12:34

0

I think this will help you. do something when one is less or equal than the other as you looking different case.

switch ([self.system.systemInbetriebnahme compare: date]) {
case NSOrderedAscending:
    // system date earlier then date
    break;
case NSOrderedSame:
    //  Same
    break;
case NSOrderedDescending:
    // system date later then date
    break;
}

answered Aug 27 '13 at 12:34

Buntylm

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I really thought it would be the answer, but it still removes the value when the case NSOrderedSame is true. – Souhail Marghabi Aug 27 '13 at 12:53

score 0 · Answer 7 · answered Aug 27 '13 at 12:36

there is no direct comparision like >= but you can do it like this

NSComparisonResult compareStart = [date1 compare: selectedDate]; // date1 is 6/6/2011 00:00
NSComparisonResult compareEnd = [date2 compare: selectedDate];   // date2 is 9/6/2011 00:00

if ((compareStart == NSOrderedAscending) || (compareStart == NSOrderedSame)
&& (compareEnd == NSOrderedDescending))
{
// date is in the right range
}

or you simply compare

if ((compareStart == NSOrderedAscending) )
{
// date is in the right range
}

zbMax · Answer 8 · 2013-08-27T13:20:49.430

0

To com[are two NSDate, this :

[[date1 earlierDate:date2] isEqualToDate: date1]

returns YES if the date1 is earlier than date2.

EDIT

if you want date1 >= date2 (later or equals to) use this condition :

([[date1 laterDate:date2] isEqualToDate: date1] || [date2 isEqualToDate:date1])

edited Aug 27 '13 at 13:20

answered Aug 27 '13 at 12:49

zbMax

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But with a minimum search in the Apple documentation, you would not have to post such a question... – zbMax Aug 27 '13 at 12:51
I am asking specificly about >= for NSDates. There was no mention in it in the app doc or results given by stackoverflow search, so I wanted to ask here. Thank you. – Souhail Marghabi Aug 27 '13 at 13:09

iOS: Compare two less or equal NSDates

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