Im in California and I had an original 1 year lease that changed after the 1st year to a month to month lease. I am moving out and am serving my landlord a 30 day notice. My question is am I able to serve this on any day of the month, say on the 7th of November, in which I would be out on the 7th of December. Which I would prorate the 7 days I'm there in December to pay the landloard. Is that OK? Or am I expected to wait to serve them the 30 day notice on the 1st of December? HELP!

Generally the safer bet is give one full rental period as notice. But we have links to CA laws at the top of this forum. You should be able to find a definitive answer in the Tenant handbook.