Cost of getting a notice wrong?

[Ramon Mota]

What if you miss a timeframe and issue a notice wrong? In my case I issued a rent increase and payment date change notice 34 days beforehand. 

Turns out the state of California allows 10% increase with a 30 day notice. Above the 10% needs 60 days. (I know things are changing and read the new law. We fall under the single family exemption.) 

I didn't know that in California about this + five days if delivered by mail rule. 

The increase sent my renter into a fit and they didn't pay all the rent telling me I can't increase it that much. In return after getting yelled at I sent a 60 day termination letter. 

If this goes to court latter about the increase needing the extra 5 days because it was issued by mail then what?

The termination letter was sent with the 5 days added and telling the renter for the time remaining the rent will not increase.