Contrasting time-qualified rules and historical processing

Pega Platform offers two separate features that can cause processing to be dependent on a date or time value. Which of these to apply to best meet an application need depends on the nature of the rules affected and the requirements and environment of the application:

• Date circumstance rules
• Historical processing capability

How circumstance rules evaluate time

Date circumstance rules are specialized versions of a base rule that only execute when certain time conditions are met.

Based on the combination of specified date property and the time interval, a rule can be resolved in one of the following ways:

Result	Date property	Start Date	End Date
Rule to be effective only if the value of the specified date property occurs within a date range	Select	Select	Select
Rule to be effective only if the value of the specified date property occurs after a certain date	Select	Select
Rule to be effective only within a date range		Select	Select
Rule to be effective only after a certain date		Select

How historical processing evaluates time

The historical processing capability applies to an entire ruleset version, not to a rule. This capability is unrelated to the concept of circumstancing and base rules.

With careful advanced design, this feature allows an application (for the current requestor) to operate according to rules as they were on a specific past date. Such processing is useful to reconstruct past behavior or apply past policies.