Comparing NSDates without time component

Question

In a swift playground, I have been using

NSDate.date() 

But, this always appears with the time element appended. For my app I need to ignor

Answer 1

There are several useful methods in NSCalendar in iOS 8.0+:

startOfDayForDate, isDateInToday, isDateInYesterday, isDateInTomorrow

And even to compare days:

func isDate(date1: NSDate!, inSameDayAsDate date2: NSDate!) -> Bool

To ignore the time element you can use this:

var toDay = Calendar.current.startOfDay(for: Date())

But, if you have to support also iOS 7, you can always write an extension

extension NSCalendar {
    func myStartOfDayForDate(date: NSDate!) -> NSDate!
    {
        let systemVersion:NSString = UIDevice.currentDevice().systemVersion
        if systemVersion.floatValue >= 8.0 {
            return self.startOfDayForDate(date)
        } else {
            return self.dateFromComponents(self.components(.CalendarUnitYear | .CalendarUnitMonth | .CalendarUnitDay, fromDate: date))
        }
    }
}

Answer 2

Use this Calendar function to compare dates in iOS 8.0+

func compare(_ date1: Date, to date2: Date, toGranularity component: Calendar.Component) -> ComparisonResult

passing .day as the unit

Use this function as follows:

let now = Date()
// "Sep 23, 2015, 10:26 AM"
let olderDate = Date(timeIntervalSinceNow: -10000)
// "Sep 23, 2015, 7:40 AM"

var order = Calendar.current.compare(now, to: olderDate, toGranularity: .hour)

switch order {
case .orderedDescending:
    print("DESCENDING")
case .orderedAscending:
    print("ASCENDING")
case .orderedSame:
    print("SAME")
}

// Compare to hour: DESCENDING

var order = Calendar.current.compare(now, to: olderDate, toGranularity: .day)


switch order {
case .orderedDescending:
    print("DESCENDING")
case .orderedAscending:
    print("ASCENDING")
case .orderedSame:
    print("SAME")
}

// Compare to day: SAME

Answer 3

When you NSDate.date() in the playground, you see the default description printed. Use NSDateFormatter to print a localized description of the date object, possibly with only the date portion.

To zero out specific portions of a date (for the sake of comparison), use NSDateComponents in conjunction with NSCalendar.

Answer 4

In Swift 4:

func compareDate(date1:Date, date2:Date) -> Bool {
    let order = NSCalendar.current.compare(date1, to: date2, toGranularity: .day)
    switch order {
    case .orderedSame:
        return true
    default:
        return false
    }
}

Answer 5

Swift:

extension NSDate {

    /**
    Compares current date with the given one down to the seconds.
    If date==nil, then always return false

    :param: date date to compare or nil

    :returns: true if the dates has equal years, months, days, hours, minutes and seconds.
    */
    func sameDate(date: NSDate?) -> Bool {
        if let d = date {
            let calendar = NSCalendar.currentCalendar()
            if NSComparisonResult.OrderedSame == calendar.compareDate(self, toDate: d, toUnitGranularity: NSCalendarUnit.SecondCalendarUnit) {
                return true
            }

        }
        return false
    }
}

Answer 6

Two Dates comparisions in swift.

    // Date comparision to compare current date and end date.
    var dateComparisionResult:NSComparisonResult = currentDate.compare(endDate)

    if dateComparisionResult == NSComparisonResult.OrderedAscending
    {
        // Current date is smaller than end date.
    }
    else if dateComparisionResult == NSComparisonResult.OrderedDescending
    {
        // Current date is greater than end date.
    }
    else if dateComparisionResult == NSComparisonResult.OrderedSame
    {
        // Current date and end date are same.
    }