T-SQL: Obtener diferencia entre fechas

FUNCION DATEDIFF ( datepart , startdate , enddate )

Parámetros

datepart

Is the part of startdate and enddate that specifies the type of boundary crossed. The following table lists all valid datepart arguments. User-defined variable equivalents are not valid.

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

startdate

Is an expression that can be resolved to a time, date, smalldatetime, datetime, datetime2, or datetimeoffset value. date can be an expression, column expression, user-defined variable or string literal. startdate is subtracted from enddate.

To avoid ambiguity, use four-digit years. For information about two digits years, see two digit year cutoff Option.

enddate

See startdate.

Ejemplo

DECLARE @startdate datetime2 = '2007-05-05 12:10:09.3312722';
DECLARE @enddate datetime2 = '2007-05-04 12:10:09.3312722';
SELECT DATEDIFF(day, @startdate, @enddate);