Calculate delay or difference between two dates in sql server
DATEDIFF (Transact-SQL)DATEDIFF ( datepart , startdate , enddate )
You can use SQL Server DateDiff function to calculate difference between two dates. This delay can be calculated in days, months, years, minutes,hours or seconds.
Here is documentation from MSDN
parameter that specifies on which part of the date to calculate the
difference. The following table lists dateparts and abbreviations
recognized by SQL Server 2005. These dateparts and abbreviations cannot
be supplied as a user-declared variable.
- startdate -
Is the starting date for the calculation. startdate is an expression that returns a datetime or smalldatetime value, or a character string in a date format.
Because smalldatetime is accurate only to the minute, when a smalldatetime value is used, seconds and milliseconds are always 0.
If you specify only the last two digits of the year, values less than or equal to the last two digits of the value of the two-digit year cutoff configuration option are in the same century as the cutoff year. Values greater than the last two digits of the value of this option are in the century that comes before the cutoff year. For example, if the two-digit year cutoff is 2049 (default), 49 is interpreted as 2049 and 2050 is interpreted as 1950. To avoid ambiguity, use four-digit years.
For more information about how to specify time values, see Time Formats. For more information about how to specify dates, see Date and Time (Transact-SQL).
Is the ending date for the calculation. enddate is an expression that returns a datetime or smalldatetime value, or a character string in a date format.
ExamplesThe following example determines the difference in days between the current date and the order date for products in the AdventureWorks database.