an estimated tax payment uses the date paid to determine penalities for the current and prior penalty periods. Withholding by default is spread equally throughout the year unless the taxpayer elects to use actual withholding for each penalty period.
penalties are calculated from the due date to the date paid. so, if you have no withholding, for quarter 1 the penalty would be from 4/17/23 until the date paid. (Not that certain disater areas had an extended date to make payments)
you can use the annualized income installment method on page 3 of the 2210 if that will reduce your penalties. It must be used for all 4 quarters so it's usually only beneficial when a substantial portion of your income is earned in the 3rd or 4th quarter.
