Nspredicate Filtered by Year Moth Day

Filter fetchRequest for year/month using NSPredicate

You cannot predicate like this, but you can create two Dates from your month and year which start day of month and end day of month.

Now you need to simply predicate like this way.

let predicate = NSPredicate(format: "%K >= %@ && %K <= %@", "DateAttribute", startDateOfMonth as NSDate, "DateAttribute", endDateOfMonth as NSDate)

Edit: If you don't know how to create date for startDateOfMonth and endDateOfMonth, then you can create it using DateComponents.

let selectedMonth = 11
let selectedYear = 2015
var components = DateComponents()
components.month = selectedMonth
components.year = selectedYear
let startDateOfMonth = Calendar.current.date(from: components)

//Now create endDateOfMonth using startDateOfMonth
components.year = 0
components.month = 1
components.day = -1
let endDateOfMonth = Calendar.current.date(byAdding: components, to: startDate!)

NSPredicate with NSDate filtering by day/month but not year

First, to extract a day and month from a date...

NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:date];
NSInteger day = [components day];
NSInteger month = [components month];

Next, (one way) to build a predicate...

[NSPredicate predicateWithBlock:^BOOL(id object, NSDictionary * bindings) {
    // object must be cast to the type of object in the list
    MyObject *myObject = (MyObject *)object;
    NSDate *creationDate = myObject.creationDate;

    // do whatever you want here, but this block must return a BOOL
}];

Putting those ideas together...

- (NSPredicate *)predicateMatchingYearAndMonthInDate:(NSDate *)date {
    NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:date];
    NSInteger day = [components day];
    NSInteger month = [components month];

    return [NSPredicate predicateWithBlock:^BOOL(id object, NSDictionary * bindings) {
        MyObject *myObject = (MyObject *)object;
        NSDate *creationDate = myObject.creationDate;
        NSDateComponents *creationComponents = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:creationDate];
        NSInteger creationDay = [creationComponents day];
        NSInteger creationMonth = [creationComponents month];
        return day == creationDay && month == creationMonth;
    }];
}

That's it. Build the predicate with some NSDate who's day and month you want to match in the array, then run that predicate on the array (filteredArrayUsingPredicate:).

NSDate *today = [NSDate date];
NSPredicate *predicate = [self predicateMatchingYearAndMonthInDate:today];
NSArray *objectsCreatedToday = [myArray filteredArrayUsingPredicate:predicate];

NSPredicate: filtering objects by day of NSDate property

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];

coredata filtering by date using NSPredicate returns nothing

date is actually a timestamp, so doing == with it will only return items which have that exact timestamp.

To get all the entries on a specific date you'll want to get the NSDate for the start of the day (startOfDay), and the NSDate for the end of the day (endOfDay) then modify the predicate to get dates between those two values using:

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"dates >= %@ AND dates >= %@", startOfDay, endOfDay];

To calculate the startOfDay and endOfDay you can either do it yourself manually or there are some other libraries you can use to calculate it such as https://github.com/erica/NSDate-Extensions.

CoreData: NSPredicate filter by date

In your model you set the dateTime property as a Date object, but you saved it as a double.

So you have to do:

dateTime = NSDate(dateWithTimeIntervalSinceReferenceDate:Double(activityInfo["eventDateTime‌​"] as! String))

Note, I don't speak Swift, so I don't know if this code could be shorter, but you get the idea.

how to build a NSPredicate filtering all days in a month using NSDate?

Yes. You need to figure out what the first instant of the month is, as well as the first instant of the next month. Here's how I would do it:

NSDate *now = [NSDate date];
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *nowComponents = [calendar components:NSEraCalendarUnit | NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit fromDate:now];
[nowComponents setDay:1];

NSDate *beginningOfCurrentMonth = [calendar dateFromComponents:nowComponents];

NSDateComponents *oneMonth = [[NSDateComponents alloc] init];
[oneMonth setMonth:1];

NSDate *beginningOfNextMonth = [calendar dateByAddingComponents:oneMonth toDate:beginningOfCurrentMonth options:0];

Once you've got those two NSDates, then you can do:

[NSPredicate predicateWithFormat:@"date >= %@ AND date < %@", beginningOfCurrentMonth, beginningOfNextMonth];

Core Data NSPredicate - Match Dates

First of all the exception occurs because the placeholder %@ is wrong. %@ is for objects, a Double value is represented by %f.

Second of all if you want to fetch all dates which are in a specific day you have to create a date range (0:00–23:59) of that day.

Using Calendar you get 0:00 with startOfDay(for:) and the end of the day by adding a day and the < operator.

For example

let calendar = Calendar.current
let startDate = calendar.startOfDay(for: selectedDate)
let endDate = calendar.date(byAdding: .day, value: 1, to: startDate)!
let predicate = NSPredicate(format: "date >= %@ AND date < %@", argumentArray: [startDate, endDate]))

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