You write:

The error I get is that it selects all recipients instead of ones that have been active for last 240 days. All the other last flags perform correctly.

I am pretty sure that there's more to this application than the script you've shown us. You seem to have added a radio button for the clast60 field with a value of 4 and a meaning of Last 240 Days in the script which offers the selection. But this is not the script doing the database query: There is no place in this code where you actually use that parameter. So I guess that you need also to make this new value known to your other script camp_copy_schedule_save.cgi. If that script has the same programming style, then a newly added value of "4" might end up in the final else branch of some if/elsif/else abomination - and treat it as if the clast60 has not been provided at all.

Good luck! You'll need it.