change state tax filing date

I have a penalty due for underpaying my estimated state taxes this year. TurboTax seems to base the penalty on the premise that I will not pay my state taxes until 4/1. (I may have told it that during the interview.) Now I want to move the date up so the penalty will include less interest. But I can't figure out how to change that in TurboTax. Can you help me with this?