Swift 3 - Comparing Date objects

Question

I'm updating my app to Swift 3.0 syntax (I know it's still in beta but I want to be prepared as soon as it released).

Until the previous Beta of Xcode (Beta 5) I was able to compare two Date objects using the operands <, > and ==. But in the latest beta (Beta 6) this isn't working any more. Here are some screenshots:

As you can see in both screenshots, these are two Date objects. But I get the following error:

What am I doing wrong? The functions are still declared in the Date class:

static func >(Date, Date)

Returns true if the left hand Date is later in time than the right hand Date.

Is this just a Beta bug or am I doing something wrong?

`let d1 = Date() ; let d2 = Date() ; if d1 > d2 { }` works in my Xcode 8 beta 6. — Martin R, Aug 18 '16 at 12:37
Yes. – You should lookup the complete error message in the Report navigator. — Martin R, Aug 18 '16 at 12:39
Thank you @MartinR! Didn't know that I can "dive" into an error and get more information. Helped me a lot! — beeef, Aug 18 '16 at 18:01

score 188 · Accepted Answer · edited Jul 14 '20 at 19:16

188

I have tried this snippet (in Xcode 8 Beta 6), and it is working fine.

let date1 = Date()
let date2 = Date().addingTimeInterval(100)

if date1 == date2 { ... }
else if date1 > date2 { ... }
else if date1 < date2 { ... }

edited Jul 14 '20 at 19:16

pkamb

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answered Aug 18 '16 at 13:12

Ankit Thakur

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if i want to ignore time. e.g. `2019-05-14 12:08:14 +0000` == `2019-05-14` should return true. then what ? – Awais Fayyaz Jun 12 '19 at 11:44
@AwaisFayyaz If you want to compare dates without taking a DateComponent into account. You need to get the components you want from the date. Then get the date from DateComponents and compare them. – Giorgio Doganiero Jul 30 '19 at 22:19

Mobile Dan · Answer 2 · 2017-10-02T22:42:46.597

`Date` is `Comparable` & `Equatable` (as of Swift 3)

This answer complements @Ankit Thakur's answer.

Since Swift 3 the Date struct (based on the underlying NSDate class) adopts the Comparable and Equatable protocols.

Comparable requires that Date implement the operators: <, <=, >, >=.
Equatable requires that Date implement the == operator.
Equatable allows Date to use the default implementation of the != operator (which is the inverse of the Equatable == operator implementation).

The following sample code exercises these comparison operators and confirms which comparisons are true with print statements.

Comparison function

import Foundation

func describeComparison(date1: Date, date2: Date) -> String {

    var descriptionArray: [String] = []

    if date1 < date2 {
        descriptionArray.append("date1 < date2")
    }

    if date1 <= date2 {
        descriptionArray.append("date1 <= date2")
    }

    if date1 > date2 {
        descriptionArray.append("date1 > date2")
    }

    if date1 >= date2 {
        descriptionArray.append("date1 >= date2")
    }

    if date1 == date2 {
        descriptionArray.append("date1 == date2")
    }

    if date1 != date2 {
        descriptionArray.append("date1 != date2")
    }

    return descriptionArray.joined(separator: ",  ")
}

Sample Use

let now = Date()

describeComparison(date1: now, date2: now.addingTimeInterval(1))
// date1 < date2,  date1 <= date2,  date1 != date2

describeComparison(date1: now, date2: now.addingTimeInterval(-1))
// date1 > date2,  date1 >= date2,  date1 != date2

describeComparison(date1: now, date2: now)
// date1 <= date2,  date1 >= date2,  date1 == date2

Suhit Patil · Answer 3 · 2020-07-15T13:00:06.730

34

from Swift 3 and above, Date is Comparable so we can directly compare dates like

let date1 = Date()
let date2 = Date().addingTimeInterval(50)

let isGreater = date1 > date2
print(isGreater)

let isSmaller = date1 < date2
print(isSmaller)

let isEqual = date1 == date2
print(isEqual)

Alternatively We can create extension on Date

extension Date {

  func isEqualTo(_ date: Date) -> Bool {
    return self == date
  }
  
  func isGreaterThan(_ date: Date) -> Bool {
     return self > date
  }
  
  func isSmallerThan(_ date: Date) -> Bool {
     return self < date
  }
}

Use: let isEqual = date1.isEqualTo(date2)

edited Jul 15 '20 at 13:00

answered Jan 11 '17 at 11:21

Suhit Patil

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1

if i want to ignore time. e.g. `2019-05-14 12:08:14 +0000` == `2019-05-14` should return true. then what ? – Awais Fayyaz Jun 12 '19 at 11:44

score 24 · Answer 4 · edited May 21 '21 at 08:24

Don't use comparators <, >, ==, !=.
Use compare(_ other: Date) function.

Usage

// Get current date
let dateA = Date()

// Get a later date (after a couple of milliseconds)
let dateB = Date()

// Compare them using switch
switch dateA.compare(dateB) {
    case .orderedAscending     :   print("Date A is earlier than date B")
    case .orderedDescending    :   print("Date A is later than date B")
    case .orderedSame          :   print("The two dates are the same")
}

// Compare them using if
if dateA.compare(dateB) == .orderedAscending {
    datePickerTo.date = datePicker.date
}

_">Don't use comparators <, >, ==, !=."_ ... Why? – Kai Huppmann Jul 29 '21 at 12:29 — Kai Huppmann, Jul 29 '21 at 12:29

score 11 · Answer 5 · answered Jan 19 '20 at 20:15

11

If you want to ignore seconds for example you can use

func isDate(Date, equalTo: Date, toUnitGranularity: NSCalendar.Unit) -> Bool

Example compare if it's the same day:

Calendar.current.isDate(date1, equalTo: date2, toGranularity: .day)

answered Jan 19 '20 at 20:15

zdravko zdravkin

2,090
19
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Your answer worked, thank u :) – steveSarsawa Jul 07 '23 at 07:14
Exactly what I was looking for, thank you very much! – marticztn Aug 25 '23 at 17:44

Jitendra Kulkarni · Answer 6 · 2017-04-05T00:44:41.713

9

For me the problem was that I had my own extension to Date class that was defining all the compare operators. Now (since swift 3) that Date is comparable, these extensions are not needed. So I commented them out and it worked.

edited Apr 05 '17 at 00:44

answered Sep 29 '16 at 17:01

Jitendra Kulkarni

823
6
17

score 8 · Answer 7 · answered Nov 21 '16 at 16:06

SWIFT 3: Don't know if this is what you're looking for. But I compare a string to a current timestamp to see if my string is older that now.

func checkTimeStamp(date: String!) -> Bool {
        let dateFormatter: DateFormatter = DateFormatter()
        dateFormatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
        dateFormatter.locale = Locale(identifier:"en_US_POSIX")
        let datecomponents = dateFormatter.date(from: date)

        let now = Date()

        if (datecomponents! >= now) {
            return true
        } else {
            return false
        }
    }

To use it:

if (checkTimeStamp(date:"2016-11-21 12:00:00") == false) {
    // Do something
}

score 6 · Answer 8 · answered May 11 '17 at 15:56

To compare date only with year - month - day and without time for me worked like this:

     let order = Calendar.current.compare(self.startDate, to: compareDate!, toGranularity: .day)  

                      switch order {
                        case .orderedAscending:
                            print("\(gpsDate) is after \(self.startDate)")
                        case .orderedDescending:
                            print("\(gpsDate) is before \(self.startDate)")
                        default:
                            print("\(gpsDate) is the same as \(self.startDate)")
                        }

score 1 · Answer 9 · answered Jun 12 '18 at 20:11

As of the time of this writing, Swift natively supports comparing Dates with all comparison operators (i.e. <, <=, ==, >=, and >). You can also compare optional Dates but are limited to <, ==, and >. If you need to compare two optional dates using <= or >=, i.e.

let date1: Date? = ...
let date2: Date? = ...
if date1 >= date2 { ... }

You can overload the <= and >=operators to support optionals:

func <= <T: Comparable>(lhs: T?, rhs: T?) -> Bool {
    return lhs == rhs || lhs < rhs
}

func >= <T: Comparable>(lhs: T?, rhs: T?) -> Bool {
    return lhs == rhs || lhs > rhs
}

score 1 · Answer 10 · answered Oct 05 '18 at 06:12

1

extension Date {
 func isBetween(_ date1: Date, and date2: Date) -> Bool {
    return (min(date1, date2) ... max(date1, date2)).contains(self)
  }
}

let resultArray = dateArray.filter { $0.dateObj!.isBetween(startDate, and: endDate) }

answered Oct 05 '18 at 06:12

Arjun Patel

1,394
14
23

score 1 · Answer 11 · answered Oct 05 '18 at 07:03

1

Another way to do it:

    switch date1.compare(date2) {
        case .orderedAscending:
            break

        case .orderedDescending:
            break;

        case .orderedSame:
            break
    }

answered Oct 05 '18 at 07:03

Shadros

728
2
10
19

score 1 · Answer 12 · answered Apr 10 '19 at 06:33

   var strDateValidate = ""
            let dateFormatter = DateFormatter()
            dateFormatter.dateFormat = "yyyy-MM-dd"

            let firstDate = dateFormatter.date(from:lblStartTime.text!)
            let secondDate = dateFormatter.date(from:lblEndTime.text!)

            if firstDate?.compare(secondDate!) == .orderedSame || firstDate?.compare(secondDate!) == .orderedAscending {
                print("Both dates are same or first is less than scecond")
                strDateValidate = "yes"
            }
            else
            {
                //second date is bigger than first
                strDateValidate = "no"
            }

            if strDateValidate == "no"
            {
                alertView(message: "Start date and end date for a booking must be equal or Start date must be smaller than the end date", controller: self)
            }

score 1 · Answer 13 · answered May 23 '19 at 09:42

Swift 5:

1) If you use Date type:

let firstDate  = Date()
let secondDate = Date()

print(firstDate > secondDate)  
print(firstDate < secondDate)
print(firstDate == secondDate)

2) If you use String type:

let firstStringDate  = "2019-05-22T09:56:00.1111111"
let secondStringDate = "2019-05-22T09:56:00.2222222"

print(firstStringDate > secondStringDate)  // false
print(firstStringDate < secondStringDate)  // true
print(firstStringDate == secondStringDate) // false

I'm not sure or the second option works at 100%. But how much would I not change the values of firstStringDate and secondStringDate the result was correct.

score 1 · Answer 14 · answered Dec 16 '19 at 21:32

1

in Swift 3,4 you should use "Compare". for example:

DateArray.sort { (($0)?.compare($1))! == .orderedDescending }

answered Dec 16 '19 at 21:32

Alireza

49
7

Swift 3 - Comparing Date objects

14 Answers14

`Date` is `Comparable` & `Equatable` (as of Swift 3)

Comparison function

Sample Use

Linked

Related

Swift 3 - Comparing Date objects

14 Answers14

Date is Comparable & Equatable (as of Swift 3)

Comparison function

Sample Use

Linked

Related

`Date` is `Comparable` & `Equatable` (as of Swift 3)