Date from Calendar.dateComponents returning nil in Swift

Question

I'm trying create a Date object with day, month and year, but the function of Calendar is returning nil.

let calendar = Calendar.current
let date = calendar.dateComponents([.day,.month,.year], from: Date()).date! // <- nil

How I create a Date object only with day, month and year?

You don't. A `Date` is a point in time. The closest you can get is midnight (locale time or UTC time or some other specific timezone of your choosing). — rmaddy, Sep 14 '18 at 19:03
if you don't care about time, Apple recommends that you set the time to noon. Daylight Saving Time may cause certain locations to have no midnight or two midnights in a day. As for how to set the time part of a date, see [this answer](https://stackoverflow.com/questions/36073704/how-to-change-the-current-days-hours-and-minutes-in-swift/36082867#36082867) — Code Different, Sep 14 '18 at 19:13

score 17 · Answer 1 · answered Sep 14 '18 at 19:32

17

As a supplement to rmaddy's answer, the reason why your code returns nil is that you try to convert DateComponents to a Date without specifying a Calendar.

If that conversion is done with a calendar method

let calendar = Calendar.current
let components = calendar.dateComponents([.day, .month, .year], from: Date())
let date = calendar.date(from: components)

or if you add the calendar to the date components

let calendar = Calendar.current
let date = calendar.dateComponents([.day, .month, .year, .calendar], from: Date()).date

then you'll get the expected result.

answered Sep 14 '18 at 19:32

Martin R

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Adding `.calendar` to the original code is a really good insight. Good Info. – rmaddy Sep 14 '18 at 19:36
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Your explanation makes sense, but in my REPL with Swift 5.2, I still get nil with your sample above... Any idea? – barley May 24 '20 at 03:39
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@barley Could be this bug: https://stackoverflow.com/a/60504976/1187415 – Martin R May 24 '20 at 03:59
@MartinR Indeed, thanks for the reply and the answer above!! – barley May 25 '20 at 22:30
@MartinR correct, I was working in the xCode debugger and the variable was showing as nil, however it actually had a value – Chuck Boris Mar 16 '21 at 13:05

score 8 · Accepted Answer · answered Sep 14 '18 at 19:08

8

If you want to strip off the time portion of a date (set it to midnight), then you can use Calendar startOfDay:

let date = Calendar.current.startOfDay(for: Date())

This will give you midnight local time for the current date.

If you want midnight of the current date for a different timezone, create a new Calendar instance and set its timeZone as needed.

answered Sep 14 '18 at 19:08

rmaddy

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For time insensitive calendrical calculations it is better to use noon – Leo Dabus Sep 14 '18 at 19:14
@LeoDabus That should be a comment on the question, not this answer. The OP simply asked how to create a date with no time. We have no idea how it is to be used. – rmaddy Sep 14 '18 at 19:16
@rmaddy A date with "no time" should be using noon – Leo Dabus Sep 14 '18 at 19:16
That's what I needed. – Augusto Sep 14 '18 at 19:17
A `Date` (As in a `Date` object) with no time does not exist. A `Date` object describes an instant in time. You can convert it to a string with just the date, or you can extract the time components from a `Date`, but a `Date` always has an associated time. – Duncan C Sep 14 '18 at 21:55
There are scenarios where a calendar program (or other time-management) software is trying to point to "a day" (and not a literal point-initime). The question might have been better with more context, rather than leaving us to speculate. – benc Aug 03 '23 at 12:41

Date from Calendar.dateComponents returning nil in Swift

2 Answers2