mp_timelimit help on tf2

Hi i’ve recently got a tf2 server and on maps such as cp_badland,cp_granary,cp_wells the time limit is the maps custom. I tried doing mp_timelimit 30 in console and I also tried rcon mp_timelimit 30 but neither of these work… all of my maps on my server have a custom time and I cant change the times on them. Please help me