sql server DATEDIFF

The DATEDIFF function in SQL Server is used to calculate the difference between two dates or times.

The syntax for DATEDIFF is as follows:

DATEDIFF(datepart, startdate, enddate)

• datepart: Specifies the part of the date or time to calculate the difference. This can be one of the following values:

  • 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)

• startdate: The starting date or time.

• enddate: The ending date or time.

Example usage:

-- Calculate the difference in days between two dates SELECT DATEDIFF(day, '2021-01-01', '2021-01-10') AS DaysDiff;

-- Calculate the difference in months between two dates SELECT DATEDIFF(month, '2021-01-01', '2021-12-31') AS MonthsDiff;

-- Calculate the difference in hours between two times SELECT DATEDIFF(hour, '09:00:00', '17:00:00') AS HoursDiff;

-- Calculate the difference in minutes between two times SELECT DATEDIFF(minute, '09:00:00', '09:30:00') AS MinutesDiff;

-- Calculate the difference in seconds between two times SELECT DATEDIFF(second, '09:00:00', '09:00:10') AS SecondsDiff