Getting the last day of a month

Question

How can I get the last day of the current month as an NSDate?

Answer 1

Version from iOS 7

just to get rid of the deprecations... with a minor addition to get the last second of the day.

    // current date
    NSDate *now = [NSDate new];

    // get last day of the current month
    NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
    [calendar setTimeZone:[NSTimeZone systemTimeZone]];

    NSRange dayRange = [ calendar rangeOfUnit:NSCalendarUnitDay
                                       inUnit:NSCalendarUnitMonth
                                      forDate:now];

    NSInteger numberOfDaysInCurrentMonth = dayRange.length;

    NSDateComponents *comp = [calendar components:
                              NSCalendarUnitYear |
                              NSCalendarUnitMonth |
                              NSCalendarUnitDay fromDate:now];

    comp.day = numberOfDaysInCurrentMonth;
    comp.hour = 24;
    comp.minute = 0;
    comp.second = 0;

    NSDate *endOfMonth = [calendar dateFromComponents:comp];

Answer 2

NSDate *curDate = [NSDate date];
        NSCalendar *currentCalendar = [NSCalendar currentCalendar];
        NSRange daysRange = [[NSCalendar currentCalendar] rangeOfUnit:NSCalendarUnitDay inUnit:NSCalendarUnitMonth
         forDate:curDate];
        NSDateComponents* comps = [currentCalendar components:NSCalendarUnitYear|NSCalendarUnitMonth|NSCalendarUnitDay fromDate:curDate];
        [comps setDay:daysRange.length];
        NSDate *maximumDate = [[NSCalendar currentCalendar] dateFromComponents:comps];

Answer 3

Put this in a category:

-(NSDate*)lastDayOfMonth
{
    NSInteger dayCount = [self numberOfDaysInMonthCount];

    NSDateComponents *comp = [[self calendar] components:
                              NSCalendarUnitYear |
                              NSCalendarUnitMonth |
                              NSCalendarUnitDay fromDate:self];

    [comp setDay:dayCount];

    return [[self calendar] dateFromComponents:comp];
}

-(NSInteger)numberOfDaysInMonthCount
{
    NSRange dayRange = [[self calendar] rangeOfUnit:NSCalendarUnitDay
                                             inUnit:NSCalendarUnitMonth
                                            forDate:self];

    return dayRange.length;
}

-(NSCalendar*)calendar
{
    NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];    
    [calendar setTimeZone:[NSTimeZone timeZoneWithName:TIMEZONE]];
    return calendar;
}

Answer 4

// Adapted from running code in my app

NSDate *curDate = [NSDate date];
NSCalendar *currentCalendar = [NSCalendar currentCalendar];
NSRange daysRange = 
[currentCalendar 
 rangeOfUnit:NSDayCalendarUnit 
 inUnit:NSMonthCalendarUnit 
 forDate:curDate];

// daysRange.length will contain the number of the last day
// of the month containing curDate

NSLog(@"%i", daysRange.length);

Answer 5

Swift version

extension NSDate {
    func lastDayOfMonth() -> NSDate {
        let calendar = NSCalendar.currentCalendar()
        let dayRange = calendar.rangeOfUnit(.Day, inUnit: .Month, forDate: self)
        let dayCount = dayRange.length
        let comp = calendar.components([.Year, .Month, .Day], fromDate: self)

        comp.day = dayCount

        return calendar.dateFromComponents(comp)!
    }
}

Answer 6

With Swift 3 & iOS 10 the easiest way I found to do this is Calendar's dateInterval(of:for:):

func monthInterval() -> DateInterval? {
    let calendar = Calendar.current
    guard let interval = calendar.dateInterval(of: .month, for: Date()) else { return nil }
    let duration = interval.duration
    // Subtract one second because dateInterval(of:for:)'s end date returns the beginning of the following month
    return DateInterval(start: interval.start, duration: duration - 1)
}

guard let interval = monthInterval() else { return }

You can then use interval.start and interval.end to get the dates you need.