What is the law in California for grace period of rent

I can't find any law in California that requires a grace period. Most landlords will provide a grace period in the lease but there is no law that requires it.

Why are you asking? Does your lease specify a period?

I can't find a grace period in my lease and I had an unexpected expense and want to pay it on the 4th. I thought there was a 5 day grace period on rentals in CA