+ Datetime addition operator

Adds a number of milliseconds to a DATETIME or a DATETIME-TZ to produce another DATETIME or DATETIME-TZ.


`datetime` + `milliseconds`


`datetime-tz` + `milliseconds`

An expression that evaluates to a DATETIME value.

An expression that evaluates to an integer value specifying a number of milliseconds.

An expression that evaluates to a DATETIME-TZ value.

This example returns the date and time exactly 24 hours later (dtTime) by calculating and adding the number of milliseconds in 24 hours to the present date and time (NOW function) and displays the result:


DEFINE VARIABLE dtTime AS DATETIME NO-UNDO. DEFINE VARIABLE iHour AS INTEGER NO-UNDO INITIAL 3600000. `dtTime = NOW + (24 * iHour)`. MESSAGE "A day later: " dtTime VIEW-AS ALERT-BOX.

To add a specific number of days and a specific number of milliseconds to a DATETIME, use the DATETIME function. For example:


new-datetime = DATETIME( DATE(old-datetime) + days, MTIME(old-datetime) + milliseconds ).

The DATETIME function ensures that the time portion remains within the valid range, by adding day(s) to the date part when the time part goes over the number of milliseconds in a day.

To add a specific number of days and milliseconds to a DATETIME-TZ, use the DATETIME-TZ function. For example:


new-datetime-tz = DATETIME-TZ( DATE(old-datetime-tz) + days, MTIME (old-datetime-tz) + milliseconds, TIMEZONE(old-dateime-tz) ).

The DATETIME-TZ function ensures that the time portion remains within the valid range, by adding day(s) to the date portion when the time part goes over the number of milliseconds in a day.