Modifying Action Diagrams › Understanding Built-In Functions › *DATE INCREMENT Rules and Examples

*DATE INCREMENT Rules and Examples

*DATE INCREMENT performs the following operation:

Start date + Increment = End date

• If a Start date is incremented by one unit (month/year), the End date is the same day in the next unit.

• If a Start date that is the last day of a month is incremented by one unit (month/year) and the next unit (month/year) is shorter than the current one, the End date is adjusted to the last day of the next unit.

As a result, the End date for the one-unit increment case is always within the contiguous unit, which can be the next or previous unit depending on the sign of the increment.

• The one-unit (month/year) increment case can be generically expanded to any combination of month(s) and/or year(s)

• When the Start date is the last day of the unit (month/year) it is always associated with the last rather than with the same day of the End unit.

• The *DATE INCREMENT result can be reversed for any day other than the last day of the month by simply changing the sign of the increment. Following is an example where the operation is reversible.

Following is an example where the operation is not reversible.

• The most confusing effect deriving from processing the last day of a month is that different Start dates (usually close to the last day of the Start month) give the same End date (always the last day of the End month) when incremented by the same unit.

This is a good example of the approximate calendar calculations mentioned previously.

Note: The everyday calendar can be widely used for business purposes. For example, to process a bank statement when the billing cycle is defined as a time interval between the first and the last day of every month.

• When the increment unit is composed of days, months, and years (*YYMMDD), then calculation is broken into two steps. First, the Start date is incremented by the months/years. Second, the adjusted intermediate date is incremented by days.

Following are the steps used to produce this result; namely, the Start date is incremented subsequently by 1 year, then by 3 months, and then by 15 days:

Note: The (*YYMMDD)' increment may not always be equal to (*DAYS); for example, if days were excluded from the calendar using a Date List or a selection parameter. However, the (*YEARS) and the (*MONTHS) always equal (*YYMMDD) and the (*YYMMDD).