“Monthly” means once every calendar month, but not sooner than 23 days after and not later than 31 days after the date in the prior month on which the event in question occurred.

Source. (See Revision Note #1 at chapter heading for Env-Or 400) #10393, eff 9-1-13; ss by #12643, eff 10-10-18 (formerly Env-Or 402.25) (See Revision Note #2 at chapter heading for Env-Or 400)