Datediff function syntax and example in sql server?

Syntax

DATEDIFF(datepart,startdate,enddate)

Where startdate and enddate are valid date expressions and datepart can be one of the following:

datepart	Abbreviation
year	yy, yyyy
quarter	qq, q
month	mm, m
dayofyear	dy, y
day	dd, d
week	wk, ww
weekday	dw, w
hour	hh
minute	mi, n
second	ss, s
millisecond	ms
microsecond	mcs
nanosecond	ns

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Example

Now we want to get the number of days between two dates.

We use the following SELECT statement:

SELECT DATEDIFF(day,'2008-06-05','2008-08-05') AS DiffDate

Result:

DiffDate

61

Example

Now we want to get the number of days between two dates (notice that the second date is "earlier" than the first date, and will result in a negative number).

We use the following SELECT statement:

SELECT DATEDIFF(day,'2008-08-05','2008-06-05') AS DiffDate

Result:

DiffDate

-61