CODEWITHSUNDEEP
objective-ccocoansdatenscalendarnsdatecomponents
becu
becu

Reputation:

How to find what day of the week for any given date using Cocoa

I'm trying to figure out what day (i.e. Monday, Friday...) of any given date (i.e. Jun 27th, 2009)

Thank you.

Upvotes: 12

Views: 22601

Answers (4)

SpokaneDude
SpokaneDude

Reputation: 4984

Here's what I wound up with, which works exactly as intended. It takes a date, alters the date to be the first of the month, and gets the day of that date:

    NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:date];
NSDateComponents *monthDateComponents = [[NSCalendar currentCalendar] components: NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear |
                                         NSCalendarUnitHour | NSCalendarUnitMinute | NSCalendarUnitSecond fromDate: date];

//  build date as start of month
monthDateComponents.year = components.year;
monthDateComponents.month = components.month;
monthDateComponents.day = 1;

NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
//    [gregorian setFirstWeekday:1];

NSDate *builtDate =[gregorian dateFromComponents: monthDateComponents];
//    NSDateComponents *weekdayComponents =[gregorian components: NSCalendarUnitWeekday fromDate: builtDate];

NSDateFormatter *df = [NSDateFormatter new];
[df setDateFormat:@"E"];

NSString *firstDay = [df stringFromDate:builtDate];
if([firstDay isEqual:@"Sun"])  //  do for the other 6 days as appropriate
    return 7;

Upvotes: -1

Jeff Hellman
Jeff Hellman

Reputation: 2117

I've been doing:

NSDateFormatter* theDateFormatter = [[[NSDateFormatter alloc] init] autorelease];
[theDateFormatter setFormatterBehavior:NSDateFormatterBehavior10_4];
[theDateFormatter setDateFormat:@"EEEE"];
NSString *weekDay =  [theDateFormatter stringFromDate:[NSDate date]];

This has the added bonus of letting you choose how you'd like the weekday to be returned (by changing the date format string in the setDateFormat: call

Lots more information at:

http://developer.apple.com/documentation/Cocoa/Conceptual/DataFormatting/Articles/dfDateFormatting10_4.html#//apple_ref/doc/uid/TP40002369

Upvotes: 28

ThibThib
ThibThib

Reputation: 8210

You may have a look to the NSDate and NSCalendar classes. For example, here and here

They provide the following code:

NSDate *today = [NSDate date];
NSCalendar *gregorian = [[NSCalendar alloc]
                         initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *weekdayComponents =
                [gregorian components:(NSDayCalendarUnit | NSWeekdayCalendarUnit) fromDate:today];
NSInteger day = [weekdayComponents day];
NSInteger weekday = [weekdayComponents weekday];

Upvotes: 16

Chuck
Chuck

Reputation: 237110

Use NSCalendar and NSDateComponents. As shown in the NSDateComponents documentation:

NSCalendar *gregorian = [[NSCalendar alloc]
initWithCalendarIdentifier:NSGregorianCalendar];
NSDate *date = [gregorian dateFromComponents:comps];
NSDateComponents *weekdayComponents = [gregorian components:NSWeekdayCalendarUnit fromDate:date];
int weekday = [weekdayComponents weekday];

Upvotes: 6

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