Release 10.1A: OpenEdge Development:
Progress 4GL Reference

INTERVAL function

Returns the time interval between two DATE, DATETIME, or DATETIME-TZ values.

Syntax

INTERVAL (datetime1, datetime2, interval-unit)

datetime1

An expression whose value is a DATE, DATETIME, or DATETIME-TZ.

datetime2

An expression whose value is a DATE, DATETIME, or DATETIME-TZ.

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.

Notes

This function returns a signed integer value (positive or negative). For example, if datetime1 is less than datetime2, the INTERVAL function returns a negative value.
If datetime1 or datetime2 is a DATE or DATETIME, the time value defaults to midnight and the time zone value defaults to the session's time zone, respectively.
You are responsible for managing value overflow, if any.