Add a time to a datetime

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Add a time to a datetime

davidgray

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October 10, 2013 at 9:14 am

#278064

Hi,
How do I add a time to a datetime? The dateadd function does not allow a time (hh:mm) as a part as far as I can see.
e.g.
DECLARE @DateTime datetime = '2013-10-16 00:00:00.000'
DECLARE @TheTime time = '11:00'
DECLARE @new datetime
I would like the resultant datetime to be '2013-10-16 11:00:00.000'
Thanks in advance

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TheSQLGuru SSC Guru Points: 134017 More actions · Answer 1

Look up DATEADD in Books Online. You can also CONVERT the date to a string and concatenate a string representation of the time and then CAST all that back to a datetime. Probably suboptimal to do that. 🙂

Best,
Kevin G. Boles
SQL Server Consultant
SQL MVP 2007-2012
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Sean Lange SSC Guru Points: 286590 More actions · Answer 2

You can cheat a little bit here since you just want to add a time datatype to a datetime.

select @DateTime + @TheTime

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davidgray SSC Eights! Points: 860 More actions · Answer 3

Sean Lange (10/10/2013)
You can cheat a little bit here since you just want to add a time datatype to a datetime.
select @DateTime + @TheTime

Hi,

that seems to work but I needed to change the type of @TheTime to a datetime.

e.g.

DECLARE @DateTime datetime = '2013-10-16 00:00:00.000'

DECLARE @TheTime datetime = '11:00'

SELECT @DateTime + @TheTime

kl25 Hall of Fame Points: 3752 More actions · Answer 4

Fairly lengthy discussion of various scenarios with adding dates and times:

Stackoverflow: How to combine date from one field with time from another field in MS SQL Server

Sean Lange SSC Guru Points: 286590 More actions · Answer 5

thedavegray (10/10/2013)
Sean Lange (10/10/2013)
You can cheat a little bit here since you just want to add a time datatype to a datetime.
select @DateTime + @TheTime
Hi,
that seems to work but I needed to change the type of @TheTime to a datetime.
e.g.
DECLARE @DateTime datetime = '2013-10-16 00:00:00.000'
DECLARE @TheTime datetime = '11:00'
SELECT @DateTime + @TheTime

OK.

select @DateTime + cast(@TheTime as time)

_______________________________________________________________

Need help? Help us help you.

Read the article at http://www.sqlservercentral.com/articles/Best+Practices/61537/ for best practices on asking questions.

Need to split a string? Try Jeff Modens splitter http://www.sqlservercentral.com/articles/Tally+Table/72993/.

Cross Tabs and Pivots, Part 1 – Converting Rows to Columns - http://www.sqlservercentral.com/articles/T-SQL/63681/
Cross Tabs and Pivots, Part 2 - Dynamic Cross Tabs - http://www.sqlservercentral.com/articles/Crosstab/65048/
Understanding and Using APPLY (Part 1) - http://www.sqlservercentral.com/articles/APPLY/69953/
Understanding and Using APPLY (Part 2) - http://www.sqlservercentral.com/articles/APPLY/69954/

davidgray SSC Eights! Points: 860 More actions · Answer 6

davidgray

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Points: 860

October 10, 2013 at 9:44 am

#1657626

Thanks for all responses.

Dwain Camps SSC Guru Points: 86948 More actions · Answer 7

Sean - Love your cheat!

Another way:

SELECT DATEADD(minute, DATEDIFF(minute, '00:00', @TheTime), @DateTime)

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