NSDate beginning of day and end of day

Question

    -(NSDate *)beginningOfDay:(NSDate *)date
{
    NSCalendar *cal = [NSCalendar currentCalendar];
    NSDateComponents *components = [cal components:( NSMonthCalendarUnit | NSYearCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit ) fromDate:date];

    [components setHour:0];
    [components setMinute:0];
    [components setSecond:0];

    return [cal dateFromComponents:components];

}

-(NSDate *)endOfDay:(NSDate *)date
{
    NSCalendar *cal = [NSCalendar currentCalendar];
    NSDateComponents *components = [cal components:(  NSMonthCalendarUnit | NSYearCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit ) fromDate:date];

    [components setHour:23];
    [components setMinute:59];
    [components setSecond:59];

    return [cal dateFromComponents:components];

}

When I call : [self endOfDay:[NSDate date]]; I get the first of the month ... Why is that? I use this two methods because I need an interval that is from the first second of the first date (beginningOfDay:date1) to the last second of the second date (endOfDay:Date2) ...

Answer 1

For swift 4

    var calendar = Calendar.current
    calendar.timeZone = NSTimeZone(abbreviation: "UTC")! as TimeZone
    let dateAtMidnight = calendar.startOfDay(for: Date())

    //For End Date
    var components = DateComponents()
    components.day = 1
    components.second = -1

    let dateAtEnd = calendar.date(byAdding: components, to: dateAtMidnight)

    print("dateAtMidnight :: \(dateAtMidnight)")
    print("dateAtEnd :: \(dateAtEnd!)")

Answer 2

My Swift extensions for NSDate:

Swift 1.2

extension NSDate {

    func beginningOfDay() -> NSDate {
        var calendar = NSCalendar.currentCalendar()
        var components = calendar.components(.CalendarUnitYear | .CalendarUnitMonth | .CalendarUnitDay, fromDate: self)
        return calendar.dateFromComponents(components)!
    }

    func endOfDay() -> NSDate {
        var components = NSDateComponents()
        components.day = 1
        var date = NSCalendar.currentCalendar().dateByAddingComponents(components, toDate: self.beginningOfDay(), options: .allZeros)!
        date = date.dateByAddingTimeInterval(-1)!
        return date
    }
}

Swift 2.0

extension NSDate {

    func beginningOfDay() -> NSDate {
        let calendar = NSCalendar.currentCalendar()
        let components = calendar.components([.Year, .Month, .Day], fromDate: self)
        return calendar.dateFromComponents(components)!
    }

    func endOfDay() -> NSDate {
        let components = NSDateComponents()
        components.day = 1
        var date = NSCalendar.currentCalendar().dateByAddingComponents(components, toDate: self.beginningOfDay(), options: [])!
        date = date.dateByAddingTimeInterval(-1)
        return date
    }
}

Answer 3

Swift 3

  class func today() -> NSDate {
        return NSDate()
    }

    class func dayStart() -> NSDate {
          return NSCalendar.current.startOfDay(for: NSDate() as Date) as NSDate
    }

    class func dayEnd() -> NSDate {
        let components = NSDateComponents()
        components.day = 1
        components.second = -1
        return NSCalendar.current.date(byAdding: components as DateComponents, to: self.dayStart() as Date)
    }

Answer 4

One more way to get result:

NSDate *date = [NSDate date];

NSDateComponents *components = [[NSDateComponents alloc] init];
components.day = [[NSCalendar currentCalendar] ordinalityOfUnit:(NSCalendarUnitDay) inUnit:(NSCalendarUnitEra) forDate:date];
NSDate *dayBegin = [[NSCalendar currentCalendar] dateFromComponents:components];

components.day += 1;
NSDate *dayEnd = [[NSCalendar currentCalendar] dateFromComponents:components];

Answer 5

In iOS 8+ this is really convenient; you can do:

let startOfDay = NSCalendar.currentCalendar().startOfDayForDate(date)

To get the end of day then just use the NSCalendar methods for 23 hours, 59 mins, 59 seconds, depending on how you define end of day.

// Swift 2.0
let components = NSDateComponents()
components.hour = 23
components.minute = 59
components.second = 59
let endOfDay = NSCalendar.currentCalendar().dateByAddingComponents(components, toDate: startOfDay, options: NSCalendarOptions(rawValue: 0))

Date Math

Apple iOS NSCalendar Documentation. (See Section: Calendrical Calculations)

NSCalendar methods discussed by NSHipster.

Answer 6

Just another way using dateInterval(of:start:interval:for:) of Calendar

On return startDate contains the start of the day and interval the number of seconds in the day.

func startAndEnd(of date : Date) -> (start : Date, end : Date) {
    var startDate = Date()
    var interval : TimeInterval = 0.0
    Calendar.current.dateInterval(of: .day, start: &startDate, interval: &interval, for: date)
    var endDate = startDate.addingTimeInterval(interval-1)
    return (start : startDate, end : endDate)
}

let (start, end) = startAndEnd(of: Date())
print(start, end)