Subtract 7 days from current date

Question

It seems that I can't subtract 7 days from the current date. This is how i am doing it:

NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *offsetComponents = [[NSDateComponents alloc] init];
[offsetComponents setDay:-7];
NSDate *sevenDaysAgo = [gregorian dateByAddingComponents:offsetComponents toDate:[NSDate date] options:0];

SevenDaysAgo gets the same value as the current date.

Please help.

EDIT: In my code I forgot to replace the variable which gets the current date with the right one. So above code is functional.

`[NSDate dateWithTimeIntervalSinceReferenceDate:[NSDate date].timeIntervalSinceReferenceDate - (7*24*60*60)]` -- Though it doesn't handle DST changes. — Hot Licks, Apr 18 '12 at 12:36
That should work. Does it work if you add 1 instead of subtract 7? How do you determine that sevenDaysAgo refers to today? — JeremyP, Apr 18 '12 at 13:19

dymv · Answer 1 · 2014-06-06T08:42:57.463

199

code:

NSDate *currentDate = [NSDate date];
NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
[dateComponents setDay:-7];
NSDate *sevenDaysAgo = [[NSCalendar currentCalendar] dateByAddingComponents:dateComponents toDate:currentDate options:0];
NSLog(@"\ncurrentDate: %@\nseven days ago: %@", currentDate, sevenDaysAgo);
[dateComponents release];

output:

currentDate: 2012-04-22 12:53:45 +0000
seven days ago: 2012-04-15 12:53:45 +0000

And I'm fully agree with JeremyP.

BR.
Eugene

edited Jun 06 '14 at 08:42

answered Apr 22 '12 at 12:56

dymv

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2

There is a memory leak in this answer though. – atuljangra Jun 05 '14 at 15:47

Dov · Answer 2 · 2017-12-05T16:56:13.090

144

If you're running at least iOS 8 or OS X 10.9, there's an even cleaner way:

NSDate *sevenDaysAgo = [[NSCalendar currentCalendar] dateByAddingUnit:NSCalendarUnitDay
                                                                value:-7
                                                               toDate:[NSDate date]
                                                              options:0];

Or, with Swift 2:

let sevenDaysAgo = NSCalendar.currentCalendar().dateByAddingUnit(.Day, value: -7,
    toDate: NSDate(), options: NSCalendarOptions(rawValue: 0))

And with Swift 3 and up it gets even more compact:

let sevenDaysAgo = Calendar.current.date(byAdding: .day, value: -7, to: Date())

edited Dec 05 '17 at 16:56

answered Feb 17 '15 at 18:26

Dov

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This should be the accepted answer as it handles all edge cases for you. – Zhivko Bogdanov Nov 29 '16 at 14:54
@ZhivkoBogdanov My answer came a few years after the accepted answer, and I don't believe you can change your accepted answer after the fact. – Dov Dec 08 '16 at 20:41
It's more for future reference than anything else. – Zhivko Bogdanov Dec 09 '16 at 11:25

score 115 · Accepted Answer · edited Dec 26 '22 at 03:32

115

use dateByAddingTimeInterval method:

NSDate *now = [NSDate date];
NSDate *sevenDaysAgo = [now dateByAddingTimeInterval:-7*24*60*60];
NSLog(@"7 days ago: %@", sevenDaysAgo);

output:

7 days ago: 2012-04-11 11:35:38 +0000

edited Dec 26 '22 at 03:32

starball

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answered Apr 18 '12 at 12:36

Novarg

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There are edge cases where this won't work properly, for example if the daylight savings changes during the seven days in question. – JeremyP Apr 18 '12 at 13:08
1

dymv's answer is the safer way of doing this. – w3bshark Sep 18 '13 at 13:11
2

This is the wrong answer for the aforementioned reasons, use dymv's answer – BarrettJ Sep 06 '14 at 02:14
1

Actually this can be done simply by: `[now dateByAddingDays:-7]` – CrashOverride Mar 05 '15 at 23:45
Doing this kind of calculation is dangerours, prefer @Dov's version. – ctietze Feb 01 '16 at 16:04

Marckaraujo · Answer 4 · 2016-11-11T17:49:50.837

68

Swift 3

Calendar.current.date(byAdding: .day, value: -7, to: Date())

edited Nov 11 '16 at 17:49

answered Sep 28 '16 at 16:23

Marckaraujo

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Don't use NSCalendar, use Calendar instead :) – Jonas Nov 11 '16 at 15:15

score 11 · Answer 5 · edited Aug 29 '21 at 13:27

11

Swift operator extension:

extension Date {
    
    static func -(lhs: Date, rhs: Int) -> Date {
        return Calendar.current.date(byAdding: .day, value: -rhs, to: lhs)!
    }
}

Usage

let today = Date()
let sevenDayAgo = today - 7

edited Aug 29 '21 at 13:27

tanmoy

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answered Nov 30 '19 at 19:53

shbedev

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Seems a good idea until you decide to subtract something thats not days – João Serra Jul 11 '22 at 14:14

score 9 · Answer 6 · answered Jan 09 '19 at 05:34

Swift 4.2 - Mutate (Update) Self

Here is another way the original poster can get one week ago if he already has a date variable (updates/mutates itself).

extension Date {
    mutating func changeDays(by days: Int) {
        self = Calendar.current.date(byAdding: .day, value: days, to: self)!
    }
}

Usage

var myDate = Date()       // Jan 08, 2019
myDate.changeDays(by: 7)  // Jan 15, 2019
myDate.changeDays(by: 7)  // Jan 22, 2019
myDate.changeDays(by: -1) // Jan 21, 2019

or

// Iterate through one week
for i in 1...7 {
    myDate.changeDays(by: i)
    // Do something
}

Babac · Answer 7 · 2015-09-23T21:07:48.267

dymv's answer work great. This you can use in swift

extension NSDate {    
    static func changeDaysBy(days : Int) -> NSDate {
        let currentDate = NSDate()
        let dateComponents = NSDateComponents()
        dateComponents.day = days
        return NSCalendar.currentCalendar().dateByAddingComponents(dateComponents, toDate: currentDate, options: NSCalendarOptions(rawValue: 0))!
    }
}

You can call this with

NSDate.changeDaysBy(-7) // Date week earlier
NSDate.changeDaysBy(14) // Date in next two weeks

Hope it helps and thx to dymv

user3069232 · Answer 8 · 2018-10-01T13:27:58.103

5

Swift 4.2 iOS 11.x Babec's solution, pure Swift

extension Date {
  static func changeDaysBy(days : Int) -> Date {
    let currentDate = Date()
    var dateComponents = DateComponents()
    dateComponents.day = days
    return Calendar.current.date(byAdding: dateComponents, to: currentDate)!
  }
}

edited Oct 01 '18 at 13:27

answered Oct 01 '18 at 13:21

user3069232

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score 4 · Answer 9 · answered Jun 25 '18 at 15:59

4

Swift 3.0+ version of the original accepted answer

Date().addingTimeInterval(-7 * 24 * 60 * 60)

However, this uses absolute values only. Use calendar answers is probably more suitable in most cases.

answered Jun 25 '18 at 15:59

originalmyth

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score 1 · Answer 10 · answered Nov 25 '21 at 05:46

1

Swift 5

Function to add or subtract day from current date.

func addOrSubtructDay(day:Int)->Date{
  return Calendar.current.date(byAdding: .day, value: day, to: Date())!
}

Now calling the function

var dayAddedDate = addOrSubtructDay(7)
var daySubtractedDate = addOrSubtructDay(-7)

To Add date pass prospective day value
To Subtract pass negative day value

answered Nov 25 '21 at 05:46

Md. Enamul Haque

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@EricAya thank your for your advice. – Md. Enamul Haque Nov 25 '21 at 12:01

score -2 · Answer 11 · edited Sep 06 '17 at 14:49

-2

Swift 3:

A modification to Dov's answer.

extension Date {

    func dateBeforeOrAfterFromToday(numberOfDays :Int?) -> Date {

        let resultDate = Calendar.current.date(byAdding: .day, value: numberOfDays!, to: Date())!
        return resultDate
    }
}

Usage:

let dateBefore =  Date().dateBeforeOrAfterFromToday(numberOfDays : -7)
let dateAfter = Date().dateBeforeOrAfterFromToday(numberOfDays : 7)
print ("dateBefore : \(dateBefore), dateAfter :\(dateAfter)")

edited Sep 06 '17 at 14:49

Dov

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answered Jul 27 '17 at 09:19

Alvin George

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Why is `numberOfDays` optional and then force-unwrapped? Shouldn't it just be a non-optional `Int`? – Dov Sep 06 '17 at 14:50
Its the proper way of containing optional value in swift function. – Alvin George Sep 07 '17 at 06:03
1

But why is numberOfDays optional? is there any time when someone will call this extension method and not give a number of days to add or remove? – Dov Sep 07 '17 at 14:51

score -3 · Answer 12 · answered Jan 03 '17 at 15:21

FOR SWIFT 3.0

here is fucntion , you can reduce days , month ,day by any count like for example here , i have reduced the current system date's year by 100 year , you can do it for day , month also just set the counter and store it in an array , you can this array anywhere then func currentTime()

 {

    let date = Date()
    let calendar = Calendar.current
    var year = calendar.component(.year, from: date)
    let month = calendar.component(.month, from: date)
    let  day = calendar.component(.day, from: date)
    let pastyear = year - 100
    var someInts = [Int]()
    printLog(msg: "\(day):\(month):\(year)" )

    for _ in pastyear...year        {
        year -= 1
                     print("\(year) ")
        someInts.append(year)
    }
          print(someInts)
        }

Subtract 7 days from current date

12 Answers12

Swift 3

Swift operator extension:

Usage

Swift 4.2 - Mutate (Update) Self

Usage

or

Linked