CODEWITHSUNDEEP
c#.netdatetime
Peter Bridger
Peter Bridger

Reputation: 9323

How to check if a DateTime occurs today?

Is there a better .net way to check if a DateTime has occured 'today' then the code below?

if ( newsStory.WhenAdded.Day == DateTime.Now.Day &&
     newsStory.WhenAdded.Month == DateTime.Now.Month &&
     newsStory.WhenAdded.Year == DateTime.Now.Year )
{ 
    // Story happened today
}
else
{ 
    // Story didn't happen today
}

Upvotes: 131

Views: 100321

Answers (12)

Anton Gogolev
Anton Gogolev

Reputation: 115897

As Guillame suggested in a comment, compare values of Date properties:

newStory.Date == DateTime.Now.Date

Upvotes: 7

guck
guck

Reputation: 71

FYI,

newsStory.Date == DateTime.Today

will return the same compare result as coding

newsStory == DateTime.Today

where newsStory is a DateTime object

.NET is smart enough to determine you want to compare based on Date only and uses that for the internal Compare. Not sure why, and actually having trouble finding documentation for this behaviour.

Upvotes: 7

pyrocumulus
pyrocumulus

Reputation: 9300

if (newsStory.WhenAdded.Date == DateTime.Today)
{

}
else
{

}

Should do the trick.

Upvotes: 260

Benjamim
Benjamim

Reputation: 552

You can implement a DateTime extension method.

Create new class for your extension methods:

namespace ExtensionMethods
{
    public static class ExtensionMethods
    {
        public static bool IsSameDay( this DateTime datetime1, DateTime datetime2 )
        {
            return datetime1.Year == datetime2.Year 
                && datetime1.Month == datetime2.Month 
                && datetime1.Day == datetime2.Day;
        }
    }
}

And now, everywhere on your code, where do you want to perform this test, you should include the using:

using ExtensionMethods;

And then, use the extension method:

newsStory.WhenAdded.IsSameDay(DateTime.Now);

Upvotes: 8

A.Polezhaev
A.Polezhaev

Reputation: 105

My solution:

private bool IsTheSameDay(DateTime date1, DateTime date2)
{
    return (date1.Year == date2.Year && date1.DayOfYear == date2.DayOfYear);
}

Upvotes: 14

Brienne Schroth
Brienne Schroth

Reputation: 2457

well, DateTime has a "Date" property and you could just compare based on that. But looking at the docs it seems that getting that property actually instantiates a new datetime with the time component set to midnight, so it may very well be slower than accessing each individual component, although much cleaner and more readable.

Upvotes: 1

Stephen Newman
Stephen Newman

Reputation: 1977

Try

if (newsStory.Date == DateTime.Now.Date) 
{ /* Story happened today */ }
else
{ /* Story didn't happen today */ }

Upvotes: 19

Polyfun
Polyfun

Reputation: 9651

How about 

if (newsStory.DayOfYear == DateTime.Now.DayOfYear)
{ // Story happened today
}

But this will also return true for 1st January 2008 and 1st January 2009, which may or may not be what you want.

Upvotes: -2

Philip Wallace
Philip Wallace

Reputation: 8035

Try this:

newsStory.Date == DateTime.Today

Upvotes: 2

Ryan Alford
Ryan Alford

Reputation: 7594

you could use DateTime.Now.DayOfYear

 if (newsStory.DayOfYear == DateTime.Now.DayOfYear)
 { // story happened today

 }
 else
 { // story didn't happen today

 }

Upvotes: -6

Lucero
Lucero

Reputation: 60276

If NewsStory was using a DateTime also, just compare the Date property, and you're done.

However, this depends what "today" actually means. If something is posted shortly before midnight, it will be "old" after a short time. So maybe it would be best to keep the exact story date (including time, preferably UTC) and check if less than 24 hours (or whatever) have passed, which is simple (dates can be subtracted, which gives you a TimeSpan with a TotalHours or TotalDays property).

Upvotes: 8

Dave D
Dave D

Reputation: 9007

if( newsStory.Date == DateTime.Today )
{
    // happened today
}

Upvotes: 32

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