About Date/Time Values in Rule Expressions
Some rule expressions contain date and time values, for example:
#{System.currentDateTime}
or
#{currentTask.taskInfo.expireDate}
These date and time values are evaluated as follows:
If a given data element within a rule expression is a java.util.Date type, it is automatically converted into epoch time in milliseconds as a java.lang.Long type. Therefore, all arithmetic and comparison operators can be applied to that value, as it now exists as a long number.