DateDiff

Retrieve the difference between two dates, measured in years.

SELECT DateDiff(“yyyy”, #13/01/1998#, #09/05/2017#);

Definition and Usage

The DATEDIFF() function computes the difference between two dates.

DateDiff(datepart, date1, date2, firstdayofweek, firstweekofyear)

Parameter	Description
datepart	Mandatory. Specifies the unit of measurement for the difference to be returned. Options include: yyyy = Year q = Quarter m = Month y = Day of the year d = Day w = Weekday ww = Week h = Hour n = Minute s = Second
date1 and date2	Mandatory. Specifies the two dates used to compute the difference.
firstdayofweek	Optional. Specifies the first day of the week, which can be set to: 0 = Use the NLS API setting 1 = Sunday (default) 2 = Monday 3 = Tuesday 4 = Wednesday 5 = Thursday 6 = Friday 7 = Saturday
firstdayofyear	Optional. Specifies the definition of the first week of the year, which can be set to: 0 = Use the NLS API setting 1 = Use the first week that includes January 1st (default) 2 = Use the first week in the year that has at least 4 days 3 = Use the first full week of the year

WORKS IN

From Access 2000

Retrieve the difference between two dates, measured in months.

SELECT DateDiff(“m”, #13/01/1998#, #09/05/2017#);

Retrieve the difference in days between a specified date and today’s date.

SELECT DateDiff(“d”, #13/01/1998#, Date());