If anyone can help with this, zakap can. He uses time based point systems for advancement on his server [gmod4president]
I'm not fully aware how he has it all set up, but know it can be done.
Now, as to whether he has time to assist or not, or perhaps make a release of his code, I do not know.
Also, does UTime work? I've not tried it since the update. Thought it was broken for some reason.
I know that zakap uses TheBigA's time script, which was written for him(zakap) originally to keep time and point count originally anyway.