An NSDate Category With Locale-Aware Calculations for Beginning, End, Next & Previous of Day, Week, Month, and Year
Thompson's Law: Any code that performs sufficiently complex date calculations using naïve arithmetic means has a non-zero chance of causing a Y2K-style collapse of the global technology infrastructure.
If your code defines kSecondsInDay, kSecondsInWeek--or worst of all--kSecondsInMonth (seriously, what would you set for that?)... you may want to reconsider. Date and time systems are really, really complicated. Between all of the time zones, calendars and other locale-specific information you should be prepared for, you really can't get it right yourself.
Thank $DEITY for NSCalendar is all I'm saying.
Anyway, this library uses NSCalendar and NSDateComponents exclusively for date calculation, so you'll handle everything from leap years to leap months like a champ.
NSLog(@"Current Time: %@", date);
NSLog(@"Beginning of Day: %@", [date beginningOfDay]);
NSLog(@"End of Day: %@", [date endOfDay]);
NSLog(@"Next Day: %@", [date nextDay]);
NSLog(@"Previous Day: %@", [date previousDay]);
NSLog(@"Beginning of Week: %@", [date beginningOfWeek]);
NSLog(@"End of Week: %@", [date endOfWeek]);
NSLog(@"Next Week: %@", [date nextWeek]);
NSLog(@"Previous Week: %@", [date previousWeek]);
NSLog(@"Beginning of Month: %@", [date beginningOfMonth]);
NSLog(@"End of Month: %@", [date endOfMonth]);
NSLog(@"Next Month: %@", [date nextMonth]);
NSLog(@"Previous Month: %@", [date previousMonth]);
NSLog(@"Beginning of Year: %@", [date beginningOfYear]);
NSLog(@"End of Year: %@", [date endOfYear]);
NSLog(@"Next Year: %@", [date nextYear]);
NSLog(@"Previous Year: %@", [date previousYear]);Result (Note the Time Zone and Daylight Savings Offsets)
Current Time: 2015-07-13 14:26:08 +0000
Beginning of Day: 2015-07-12 22:00:00 +0000
End of Day: 2015-07-13 21:59:59 +0000
Next Day: 2015-07-14 14:26:08 +0000
Previous Day: 2015-07-12 14:26:08 +0000
Beginning of Week: 2015-07-12 22:00:00 +0000
End of Week: 2015-07-19 21:59:59 +0000
Next Week: 2015-07-20 14:26:08 +0000
Previous Week: 2015-07-06 14:26:08 +0000
Beginning of Month: 2015-06-30 22:00:00 +0000
End of Month: 2015-07-31 21:59:59 +0000
Next Month: 2015-08-13 14:26:08 +0000
Previous Month: 2015-06-13 14:26:08 +0000
Beginning of Year: 2014-12-31 23:00:00 +0000
End of Year: 2015-12-31 22:59:59 +0000
Next Year: 2016-07-13 14:26:08 +0000
Previous Year: 2014-07-13 14:26:08 +0000
Mattt Thompson
"A Cupertino Yankee in Scott Forstall's Court" is available under the MIT license. See the LICENSE file for more info.