Assigning an Effectivity to an If-Then Rule 
When you want an if-then Rule to be executed during a specific time period, you should create an effectivity and assign it to the if then rule.
Prerequisites
You should have already created an If-Then rule.
Procedure
Locate the ruleset (Where is my ruleset?) and double-click the ruleset.
In the Project Explorer view or the Outline view, expand the Rules folder and choose a rule node.
NoteIf you do not see the Outline view, choose
Window 
Show View Other 
.In the dialog box that appears, expand the General node and choose Outline. Choose OK.
End of the note.In the rule editor, in the Effectivity section, choose the default value and in the drop down menu, choose an effectivity name.
Save your changes.