How to convert DateTime? to DateTime

Question

I want to convert a nullable DateTime (DateTime?) to a DateTime, but I am getting an error:

Cannot implicitly convert type 'System.DateTime?' to 'System.DateTime'. An explicit conversion exists (are you missing a cast?)

I have attempted the following:

DateTime UpdatedTime = (DateTime)_objHotelPackageOrder.UpdatedDate == null 
    ? DateTime.Now : _objHotelPackageOrder.UpdatedDate;

chills42 · Accepted Answer · 2009-07-07 11:54:23Z

360

You want to use the null-coalescing operator, which is designed for exactly this purpose.

Using it you end up with this code.

DateTime UpdatedTime = _objHotelPackageOrder.UpdatedDate ?? DateTime.Now;

answered Jul 7, 2009 at 11:54

chills42

14.6k4 gold badges45 silver badges78 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Ravi Ram Over a year ago

here is a snippet I used within a Presenter filling a view with a Nullable Date/Time : memDateLogin = m.memDateLogin ?? DateTime.MinValue

Vasil Valchev Over a year ago

'DateTime?' dose not contain definition for 'UpdatedDate'

Josh · Accepted Answer · 2009-07-07 12:29:49Z

98

MS already made a method for this, so you dont have to use the null coalescing operator. No difference in functionality, but it is easier for non-experts to get what is happening at a glance.

DateTime updatedTime = _objHotelPackageOrder.UpdatedDate.GetValueOrDefault(DateTime.Now);

answered Jul 7, 2009 at 12:29

Josh

1,1177 silver badges11 bronze badges

Comments

Valentin V · Accepted Answer · 2009-07-07 11:50:32Z

44

Try this

DateTime UpdatedTime = _objHotelPackageOrder.UpdatedDate ?? DateTime.Now;

answered Jul 7, 2009 at 11:50

Valentin V

25.9k34 gold badges110 silver badges154 bronze badges

1 Comment

spolto Over a year ago

The key thing here is the null-coalescing operator, see chills42's answer more information.

César León · Accepted Answer · 2023-07-18 14:27:56Z

36

You can use a simple cast:

DateTime dtValue = (DateTime) dtNullAbleSource;

You have to check if the var is null before

edited Jul 18, 2023 at 14:27

answered Sep 6, 2016 at 14:02

César León

3,1001 gold badge23 silver badges18 bronze badges

1 Comment

Leandro Bardelli Over a year ago

Perfect if you check if the var is null before +1

adrianbanks · Accepted Answer · 2009-07-07 11:57:22Z

27

You need to call the Value property of the nullable DateTime. This will return a DateTime.

Assuming that UpdatedDate is DateTime?, then this should work:

DateTime UpdatedTime = (DateTime)_objHotelPackageOrder.UpdatedDate == null ? DateTime.Now : _objHotelPackageOrder.UpdatedDate.Value;

To make the code a bit easier to read, you could use the HasValue property instead of the null check:

DateTime UpdatedTime = _objHotelPackageOrder.UpdatedDate.HasValue
                          ? _objHotelPackageOrder.UpdatedDate.Value
                          : DateTime.Now;

This can be then made even more concise:

DateTime UpdatedTime = _objHotelPackageOrder.UpdatedDate ?? DateTime.Now;

edited Jul 7, 2009 at 11:57

answered Jul 7, 2009 at 11:49

adrianbanks

83.3k23 gold badges180 silver badges208 bronze badges

Comments

Simon Wilson · Accepted Answer · 2009-07-10 12:39:41Z

6

How about the following:

DateTime UpdatedTime = _objHotelPackageOrder.UpdatedDate.HasValue ? _objHotelPackageOrder.UpdatedDate.value : DateTime.Now;

edited Jul 10, 2009 at 12:39

answered Jul 7, 2009 at 11:50

Simon Wilson

10.5k3 gold badges30 silver badges26 bronze badges

Comments

Ravi Ram · Accepted Answer · 2012-07-12 05:01:28Z

6

Here is a snippet I used within a Presenter filling a view with a Nullable Date/Time

memDateLogin = m.memDateLogin ?? DateTime.MinValue

answered Jul 12, 2012 at 5:01

Ravi Ram

24.5k21 gold badges89 silver badges119 bronze badges

Comments

Mateusz Rogulski · Accepted Answer · 2012-09-26 12:31:47Z

3

You can also try Nullable(T) Properties:

DateTime UpdatedTime = _objHotelPackageOrder.UpdatedDate.HasValue 
    ? DateTime.Now : _objHotelPackageOrder.UpdatedDate.Value;

answered Sep 26, 2012 at 12:31

Mateusz Rogulski

7,4638 gold badges47 silver badges62 bronze badges

Comments

B--rian · Accepted Answer · 2019-12-05 11:16:58Z

1

Consider using the following which its far better than the accepted answer

DateTime UpdatedTime = _objHotelPackageOrder.UpdatedDate == null 
    ? DateTime.Now : (DateTime)_objHotelPackageOrder.UpdatedDate;

edited Dec 5, 2019 at 11:16

B--rian

5,97611 gold badges50 silver badges101 bronze badges

answered Oct 22, 2015 at 11:48

Sadiqabbas Hirani

3871 gold badge5 silver badges14 bronze badges

1 Comment

n4rzul Over a year ago

Care to say why its better?

Timothy S. Van Haren · Accepted Answer · 2009-07-07 11:49:27Z

0

Try this:

DateTime UpdatedTime = (DateTime)_objHotelPackageOrder.UpdatedDate == null ? DateTime.Now : _objHotelPackageOrder.UpdatedDate.Value;

answered Jul 7, 2009 at 11:49

Timothy S. Van Haren

8,9762 gold badges32 silver badges34 bronze badges

Comments

Harsh Vyas · Accepted Answer · 2016-11-16 07:49:14Z

0

DateTime UpdatedTime = _objHotelPackageOrder.HasValue ? _objHotelPackageOrder.UpdatedDate.Value : DateTime.Now;

answered Nov 16, 2016 at 7:49

Harsh Vyas

3264 silver badges14 bronze badges

2 Comments

Maximilian Ast Over a year ago

It's normaly considered good form to explain your suggestions/answers. Code only answers can be surprisingly uninformative, even if they are technically correct.

Harsh Vyas Over a year ago

@MaximilianAst yes you are right will try to implement the way you have suggested :)

workaktive · Accepted Answer · 2022-06-22 07:27:52Z

0

You can also use the IS operator starting with C# 7.0:

DateTime UpdatedTime = (_objHotelPackageOrder.UpdatedDate is DateTime myDate) ? myDate : DateTime.Now;

Or in a case distinction

if (_objHotelPackageOrder.UpdatedDate is DateTime UpdatedTime)
{
   ...
}

For the sake of completeness.

answered Jun 22, 2022 at 7:27

workaktive

1

Collectives™ on Stack Overflow

How to convert DateTime? to DateTime

12 Answers 12

2 Comments

Comments

1 Comment

1 Comment

Comments

Comments

Comments

Comments

1 Comment

Comments

2 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

12 Answers 12

2 Comments

Comments

1 Comment

1 Comment

Comments

Comments

Comments

Comments

1 Comment

Comments

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related