获取当前年月日和星期

NSDate *date1 = [NSDate
date];
NSCalendar *calendar = [NSCalendar
currentCalendar];
NSDateComponents *comps;

// 年月日获得
comps = [calendar components:(NSCalendarUnitYear |
NSCalendarUnitMonth | NSCalendarUnitDay)
fromDate:date];
NSInteger year = [comps
year];
NSInteger month = [comps
month];
NSInteger day = [comps
day];
NSLog(@"year: %ld month: %ld, day: %ld", (long)year, (long)month,
(long)day);
// NSCalendarUnitWeekdayOrdinal
comps = [calendar components:(NSCalendarUnitCalendar |
NSCalendarUnitWeekday | NSCalendarUnitWeekdayOrdinal)

fromDate:date];
NSInteger week = [comps
weekOfYear]; //
今年的第几周
NSInteger weekday = [comps
weekday]; //
星期几（注意，周日是“1”，周一是“2”。。。。）
NSInteger weekdayOrdinal = [comps
weekdayOrdinal]; //
这个月的第几周
NSLog(@"week: %ld weekday: %ld ordinal: %ld", (long)week, (long)weekday,
(long)weekdayOrdinal);