DATEADD()

Procedural SQL (PSQL) StatementsAggregate Functions

`DATEADD()`

Adds or subtracts datetime units from a datetime value

Result type

DATE, TIME or TIMESTAMP

Syntax

DATEADD (<args>)

<args> ::=
    <amount> <unit> TO <datetime>
  | <unit>, <amount>, <datetime>

<amount> ::= an integer expression (negative to subtract)
<unit> ::=
    YEAR | MONTH | WEEK | DAY
  | HOUR | MINUTE | SECOND | MILLISECOND
<datetime> ::= a DATE, TIME or TIMESTAMP expression

Table 1. `DATEADD` Function Parameters
Parameter	Description
amount	An integer expression of the `SMALLINT`, `INTEGER` or `BIGINT` type.For unit `MILLISECOND`, the type is `NUMERIC(18, 1)`.A negative value is subtracted.
unit	Date/time unit
datetime	An expression of the `DATE`, `TIME` or `TIMESTAMP` type

Adds the specified number of years, months, weeks, days, hours, minutes, seconds or milliseconds to a date/time value.

The result type is determined by the third argument.
With TIMESTAMP and DATE arguments, all units can be used.
With TIME arguments, only HOUR, MINUTE, SECOND and MILLISECOND can be used.

Examples of `DATEADD`

dateadd (28 day to current_date)
dateadd (-6 hour to current_time)
dateadd (month, 9, DateOfConception)
dateadd (-38 week to DateOfBirth)
dateadd (minute, 90, cast('now' as time))
dateadd (? year to date '11-Sep-1973')

select
  cast(dateadd(-1 * extract(millisecond from ts) millisecond to ts) as varchar(30)) as t,
  extract(millisecond from ts) as ms
from (
  select timestamp '2014-06-09 13:50:17.4971' as ts
  from rdb$database
) a

T                        MS
------------------------ ------
2014-06-09 13:50:17.0000  497.1

DATEADD()

DATEADD()

Examples of DATEADD

`DATEADD()`

Examples of `DATEADD`