IsValidBusinessDay function do not work correctly for Closed day
IsValidBusinessDay and @isBusinessDay() functions do not work correctly for Closed Days. This occurs in the Australia timezone when the system contains a Calendar prior to 1972.
Steps to Reproduce
Create a Calendar instance with start date as 1970/01/01 in Australia time zone. Validate the Closed Days using @isBusinessDay() or IsValidBusinessDay function.
A defect in Pegasystems’ code or rules.