Adds a time interval to, or subtracts a time
interval from, a DATE, DATETIME, or DATETIME-TZ value, and returns
the new value.
Syntax
ADD-INTERVAL (datetime, interval-amount, interval-unit)
|
-
datetime
- An expression whose value is a DATE, DATETIME, or DATETIME-TZ.
-
interval-amount
- A signed integer (positive or negative) indicating the amount
of time you want to add to or subtract from datetime value.
-
interval-unit
- A character constant, or a character expression that evaluates
to one of the following time units: ‘years', ‘months', ‘weeks',
‘days', 'hours', ‘minutes', ‘seconds' or ‘milliseconds'. These values
are case insensitive and may be singular.
Note
To add
or subtract months or years, this function converts the date to Gregorian
before adding or subtracting the year or month value. If the result
is an invalid date, the function decrements the day part of the
date until a valid date is obtained. For example:
- Adding
1 month to January 30, 2003 yields February 28, 2003
- Adding 13 months to January 30, 2003 yields February 29, 2004
(2004 is a leap year)
- Subtracting 1 month from December 31, 2003 yields November 30, 2003
