What is the best way to perform a date comparison in a decision table?

Issue

• If you have a decision table where one of the condition columns is used to compare a date, to see if the test value is more recent than a certain value. For example, the values are 3 months ago and 9 months ago. You can use the following code:

  
  new Date(new Date().getYear(), new Date().getMonth() - 9, new Date().getDate())
  
  

  but this code is not fine for a business analyst.

• What is the best way to perform a date comparison in a decision table?