Day of the week of the first day of the month

Question

I need to get the day of the week on the first day of the month. For example, for the current month of September 2013, the first day falls on Sunday.

Answer 1

First select the first day of the current month (for example):

NSDate *today = [NSDate date]; NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; NSDateComponents *components = [gregorian components:(NSEraCalendarUnit | NSYearCalendarUnit | NSMonthCalendarUnit) fromDate:today]; components.day = 1; NSDate *firstDayOfMonth = [gregorian dateFromComponents:components]; 

Then use NSDateFormatter to print on a weekday:

 NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; [dateFormatter setDateFormat:@"EEEE"]; NSLog(@"%@", [dateFormatter stringFromDate:firstDayOfMonth]); 

PS also see Date Format Formats

Answer 2

Here is the solution to get the name of the day of the week of the first day in the current month

 NSDateComponents *weekdayComps = [[NSDateComponents alloc] init]; weekdayComps = [calendar.currentCalendar components:calendar.unitFlags fromDate:calendar.today]; weekdayComps.day = 1; NSDateFormatter *weekDayFormatter = [[NSDateFormatter alloc]init]; [weekDayFormatter setDateFormat:@"EEEE"]; NSString *firstweekday = [weekDayFormatter stringFromDate:[calendar.currentCalendar dateFromComponents:weekdayComps]]; NSLog(@"FIRST WEEKDAY: %@", firstweekday); 

For week week index use this

 NSDate *weekDate = [calendar.currentCalendar dateFromComponents:weekdayComps]; NSDateComponents *components = [calendar.currentCalendar components: NSWeekdayCalendarUnit fromDate: weekDate]; NSUInteger weekdayIndex = [components weekday]; NSLog(@"WEEKDAY INDEX %i", weekdayIndex); 

If necessary, you can increase or decrease the month.

Answer 3

Depending on the output, you can use NSDateFormatter (as already mentioned), or you can use the NSDateComponents class. NSDateFormatter will give you a string representation, NSDateComponents will give you integer values. The weekday method can do what you want.

 NSDateComponents *components = ...; NSInteger val = [components weekday]; 

Answer 4

For Swift 4.2

The first:

 extension Calendar { func startOfMonth(_ date: Date) -> Date { return self.date(from: self.dateComponents([.year, .month], from: date))! } } 

Secondly:

 self.firstWeekDay = calendar.component(.weekday, from: calendar.startOfMonth(Date()))