How can I get the year/month/day of a
NSCalendar *cal = [[NSCalendar alloc] init];
NSDateComponents *components = [cal components:0 fromDate:date];
int year = [components year];
int month = [components month];
int day = [components day];
Because this is apparently my most popular answer, I'll try to edit it to contain a little bit more information.
Despite its name,
NSDate in and of itself simply marks a point in machine time, not a date. There's no correlation between the point in time specified by an
NSDate and a year, month, or day. For that, you have to refer to a calendar. Any given point in time will return different date information based on what calendar you're looking at (dates are not the same in both the Gregorian and Jewish calendars, for instance), and while the Gregorian calendar is the most widely used calendar in the world - I'm assuming - we're a little biased that
NSDate should always use it.
NSDate, luckily, is far more bipartisan.
Getting date and time is going to have to pass through
NSCalendar, as you mentioned, but there's a simpler way to do it:
NSDateComponents *components = [[NSCalendar currentCalendar] components:NSCalendarUnitDay | NSCalendarUnitMonth | NSCalendarUnitYear fromDate:[NSDate date]];
That generates an
NSDateComponents object containing the day, month, and year from the current system calendar for the current day. (Note: this isn't necessarily the current user-specified calendar, just the default system one.)
Of course, if you're using a different calendar or date, you can easily change that. A list of available calendars and calendar units can be found in the
NSCalendar Class Reference. More information about
NSDateComponents can be found in the
NSDateComponents Class Reference.
For reference, accessing individual components from the
NSDateComponents is rather easy:
NSInteger day = [components day]; NSInteger month = [components month]; NSInteger year = [components year];
You just have to be mindful:
NSDateComponents won't contain valid information for any fields you ask for unless you generated them with that valid information (i.e. request
NSCalendar to provide that information with
NSDateComponents contain no reference information in and of themselves - they're just simple structures that hold numbers for you to access. If you want to also get an era, for instance, out of
NSDateComponents, you'll have to feed the generator method from
NSCalendar with the