California wants estimated payments from anyone expecting to owe at least $500 ($250 married/RDP filing separately) after withholding. The amount is the smaller of 90% of this year's tax or 100% of last year's - 110% if last year's California AGI was over $150,000 ($75,000 separately) - and at $1,000,000 of this year's AGI ($500,000 separately) only 90% of this year counts. California differs from federal: 30% by April 15, 40% by June 15, nothing in September, 30% by January 15. The federal payments are four equal quarters on the same dates plus September. A weekend moves a date to Monday; holidays are not counted here.
A California payment counts toward the installments due on or after its date. Each needs its FTB confirmation number (Web Pay, MyFTB or a card payment) before it is recorded. The penalty itself is figured on Form 5805.