Why is TurboTax telling me I need to make only 3 estimated state tax payments for 2021?

[rainonthefarm]

Just completed my 2020 taxes, but I find it odd that TurboTax is telling me that I need to make only three estimated state tax payments for 2021.  TurboTax says I need to make payments on 4/15/2021, 6/15/2021, and 1/15/2022, but not on 9/15/2021.  My state is California.  I've never seen this before.  Is this a bug?  

For Federal estimated tax payments, TurboTax says I need to make the usual four payments, as expected.

[LenaH · Accepted solution]

No, it is not a bug in TurboTax. Per the 2021 Instructions for Form 540-ES, installments due shall be 30% of the required annual payment for the 1st required installment, 40% of the required annual payment for the 2nd required installment, no installment is due for the 3rd required installment, and 30% of the required annual payment for the 4th required installment.

2021 Instructions for 540-ES

[rainonthefarm]

Thank you, Lena.  And shame on me for not reading the instructions for form 540-ES.  Your answer is much appreciated.