NSPredicate: filtering objects by day of NSDate property

Question

I have a Core Data model with an NSDate property. I want to filter the database by day. I assume the solution will involve an NSPredicate, but I'm not sure how to put it all together.

I know how to compare the day of two NSDates using NSDateComponents and NSCalendar, but how do I filter it with an NSPredicate?

Perhaps I need to create a category on my NSManagedObject subclass that can return a bare date with just the year, month and day. Then I could compare that in an NSPredicate. Is this your recommendation, or is there something simpler?

score 197 · Accepted Answer · answered Dec 27 '09 at 09:17

197

Given a NSDate * startDate and endDate and a NSManagedObjectContext * moc:

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(date >= %@) AND (date <= %@)", startDate, endDate];
NSFetchRequest *request = [[[NSFetchRequest alloc] init] autorelease];
[request setEntity:[NSEntityDescription entityForName:@"EntityName" inManagedObjectContext:moc]];
[request setPredicate:predicate];

NSError *error = nil;
NSArray *results = [moc executeFetchRequest:request error:&error];

answered Dec 27 '09 at 09:17

diciu

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what if we have only one date? – Wasim Sep 14 '11 at 09:55
4

Looks like you can use `==`. Though if you're searching by day, remember that NSDate is a date-and-time -- you might want to use a midnight-to-midnight range. – jlstrecker Oct 17 '11 at 15:45
1

Example on how to also setup startDate and endDate, see my answer below – d.ennis Nov 13 '11 at 22:13
@jlstrecker can u show me an example how to use a midnight to midnight range. for example: i have 2 same days but different timing. and i want to filter by day(i dont care about the timing). How can i do that? – iosMentalist Sep 07 '12 at 13:47
3

@Shady In the above example, you could set `startDate` to 2012-09-17 0:00:00 and `endDate` to 2012-09-18 0:00:00 and the predicate to startDate <= date < endDate. That would catch all times on 2012-09-17. – jlstrecker Sep 17 '12 at 23:34
@diciu I'v tried the exactly same predicate as yours: @"(startDate >= %@) AND (startDate <= %@)", self.minDate, self.maxDate]" but i'm still getting the error! 'Unable to parse the format string "(startDate >= 2014-07-14 23:46:05 +0000) AND (startDate <= 2014-07-19 12:48:19 +0000)"' What am I doing wrong here!?? Is the format wrong?? – MQoder Jul 20 '14 at 22:50
@MQoder are those NSDates, or strings? – quellish Aug 15 '14 at 10:49
@quellish the "startDate" is a NSDate object. What I did wrong was passing a string to the predicate instead of creating te predicate on the fly. I solved it by using NSCompoundPredicate. – MQoder Aug 17 '14 at 14:06
My dates are in Swift 3 native format (value type `Date`), so I had to use `as NSDate` to silence a compiler error. – Nicolas Miari Feb 03 '17 at 09:55

score 64 · Answer 2 · edited Nov 13 '18 at 04:32

Example on how to also set up startDate and endDate to the above given answer:

...

NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:(NSCalendarUnitYear | NSCalendarUnitMonth ) fromDate:[NSDate date]];
//create a date with these components
NSDate *startDate = [calendar dateFromComponents:components];
[components setMonth:1];
[components setDay:0]; //reset the other components
[components setYear:0]; //reset the other components
NSDate *endDate = [calendar dateByAddingComponents:components toDate:startDate options:0];
predicate = [NSPredicate predicateWithFormat:@"((date >= %@) AND (date < %@)) || (date = nil)",startDate,endDate];

...

Here I was searching for all entries within one month. It's worth to mention, that this example also shows how to search 'nil' date-entires.

score 12 · Answer 3 · answered Oct 09 '16 at 13:27

Swift 3.0 extension for Date:

extension Date{

func makeDayPredicate() -> NSPredicate {
    let calendar = Calendar.current
    var components = calendar.dateComponents([.year, .month, .day, .hour, .minute, .second], from: self)
    components.hour = 00
    components.minute = 00
    components.second = 00
    let startDate = calendar.date(from: components)
    components.hour = 23
    components.minute = 59
    components.second = 59
    let endDate = calendar.date(from: components)
    return NSPredicate(format: "day >= %@ AND day =< %@", argumentArray: [startDate!, endDate!])
}
}

Then use like:

 let fetchReq = NSFetchRequest(entityName: "MyObject")
 fetchReq.predicate = myDate.makeDayPredicate()

score 10 · Answer 4 · answered May 27 '15 at 13:36

In Swift I got something similar to:

        let dateFormatter = NSDateFormatter()
        dateFormatter.dateFormat = "yyyy-MM-dd"
        let date = dateFormatter.dateFromString(predicate)
        let calendar = NSCalendar(calendarIdentifier: NSGregorianCalendar)
        let components = calendar!.components(
            NSCalendarUnit.CalendarUnitYear |
                NSCalendarUnit.CalendarUnitMonth |
                NSCalendarUnit.CalendarUnitDay |
                NSCalendarUnit.CalendarUnitHour |
                NSCalendarUnit.CalendarUnitMinute |
                NSCalendarUnit.CalendarUnitSecond, fromDate: date!)
        components.hour = 00
        components.minute = 00
        components.second = 00
        let startDate = calendar!.dateFromComponents(components)
        components.hour = 23
        components.minute = 59
        components.second = 59
        let endDate = calendar!.dateFromComponents(components)
        predicate = NSPredicate(format: "day >= %@ AND day =< %@", argumentArray: [startDate!, endDate!])

I had a hard time to discover that string interpolation "\(this notation)" doesn't work for comparing dates in NSPredicate.

Thank you for this answer. Swift 3 version added below. – DS. Sep 10 '16 at 21:30 — DS., Sep 10 '16 at 21:30

score 8 · Answer 5 · edited May 23 '17 at 11:54

I ported the answer from Glauco Neves to Swift 2.0 and wrapped it inside a function that receives a date and returns the NSPredicate for the corresponding day:

func predicateForDayFromDate(date: NSDate) -> NSPredicate {
    let calendar = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)
    let components = calendar!.components([.Year, .Month, .Day, .Hour, .Minute, .Second], fromDate: date)
    components.hour = 00
    components.minute = 00
    components.second = 00
    let startDate = calendar!.dateFromComponents(components)
    components.hour = 23
    components.minute = 59
    components.second = 59
    let endDate = calendar!.dateFromComponents(components)

    return NSPredicate(format: "day >= %@ AND day =< %@", argumentArray: [startDate!, endDate!])
}

Thank you for this answer. Swift 3 version added below. – DS. Sep 10 '16 at 21:30 — DS., Sep 10 '16 at 21:30

score 6 · Answer 6 · answered Sep 10 '16 at 21:29

Adding to Rafael's answer (incredibly useful, thank you!), porting for Swift 3.

func predicateForDayFromDate(date: Date) -> NSPredicate {
    let calendar = Calendar(identifier: Calendar.Identifier.gregorian)
    var components = calendar.dateComponents([.year, .month, .day, .hour, .minute, .second], from: date)
    components.hour = 00
    components.minute = 00
    components.second = 00
    let startDate = calendar.date(from: components)
    components.hour = 23
    components.minute = 59
    components.second = 59
    let endDate = calendar.date(from: components)

    return NSPredicate(format: "YOUR_DATE_FIELD >= %@ AND YOUR_DATE_FIELD =< %@", argumentArray: [startDate!, endDate!])
}

andrewbuilder · Answer 7 · 2020-08-11T05:52:53.040

Building on the previous answers, an update and alternative method using Swift 5.x

func predicateForDayUsingDate(_ date: Date) -> NSPredicate {
    
    var calendar = Calendar.current
    calendar.timeZone = NSTimeZone.local
    // following creates exact midnight 12:00:00:000 AM of day
    let startOfDay = calendar.startOfDay(for: date)
    // following creates exact midnight 12:00:00:000 AM of next day
    let endOfDay = calendar.date(byAdding: .day, value: 1, to: startOfDay)!
    
    return NSPredicate(format: "day >= %@ AND day < %@", argumentArray: [startOfDay, endOfDay])
}

If you'd prefer to create the time for endOfDay as 11:59:59 PM, you can instead include...

    let endOfDayLessOneSecond = endOfDay.addingTimeInterval(TimeInterval(-1))

but then you might change the NSPredicate to...

    return NSPredicate(format: "day >= %@ AND day <= %@", argumentArray: [startOfDay, endOfDayLessOneSecond])

...with specific note of the change from day < %@ to day <= %@.

score 1 · Answer 8 · answered Apr 05 '16 at 04:58

I've recently spent some time attempting to solve this same problem and add the following to the list of alternatives to prepare start and end dates (includes updated method for iOS 8 and above)...

NSDate *dateDay = nil;
NSDate *dateDayStart = nil;
NSDate *dateDayNext = nil;

dateDay = <<USER_INPUT>>;

dateDayStart = [[NSCalendar currentCalendar] startOfDayForDate:dateDay];

//  dateDayNext EITHER
dateDayNext = [dateDayStart dateByAddingTimeInterval:(24 * 60 * 60)];

//  dateDayNext OR
NSDateComponents *dateComponentDay = nil;
dateComponentDay = [[NSDateComponents alloc] init];
[dateComponentDay setDay:1];
dateDayNext = [[NSCalendar currentCalendar] dateByAddingComponents:dateComponentDay
                                                            toDate:dateDayStart
                                                           options:NSCalendarMatchNextTime];

...and the NSPredicate for the Core Data NSFetchRequest (as already shown above in other answers)...

[NSPredicate predicateWithFormat:@"(dateAttribute >= %@) AND (dateAttribute < %@)", dateDayStart, dateDayNext]]

score 0 · Answer 9 · answered Nov 07 '15 at 10:51

For me this is worked.

NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDateComponents *components = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit ) fromDate:[NSDate date]];
    //create a date with these components
    NSDate *startDate = [calendar dateFromComponents:components];
    [components setMonth:0];
    [components setDay:0]; //reset the other components
    [components setYear:0]; //reset the other components
    NSDate *endDate = [calendar dateByAddingComponents:components toDate:startDate options:0];

    startDate = [NSDate date];
    endDate = [startDate dateByAddingTimeInterval:-(7 * 24 * 60 * 60)];//change here

    NSString *startTimeStamp = [[NSNumber numberWithInt:floor([endDate timeIntervalSince1970])] stringValue];
    NSString *endTimeStamp = [[NSNumber numberWithInt:floor([startDate timeIntervalSince1970])] stringValue];


   NSPredicate *predicate = [NSPredicate predicateWithFormat:@"((paidDate1 >= %@) AND (paidDate1 < %@))",startTimeStamp,endTimeStamp];
    NSLog(@"predicate is %@",predicate);
    totalArr = [completeArray filteredArrayUsingPredicate:predicate];
    [self filterAndPopulateDataBasedonIndex];
    [self.tableviewObj reloadData];
    NSLog(@"result is %@",totalArr);

I have filtered array from current date to 7 days back. I mean I am getting one week data from current date. This should work.

Note: I am converting date which is coming with milli seconds by 1000, and comparing after. Let me know if you need any clarity.

In your answer `completeArray` is it having Array of `dictionary` or `dataModel` I want to apply on DataModel. — Sumeet Mourya, Jun 14 '17 at 06:02

NSPredicate: filtering objects by day of NSDate property

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