# Solve for level payment with a twist

Reworded trying to clarify. Also corrected example to correctly state 4 years and 150 days.

I'm struggling with how to solve for a level withdrawal that will reduce a starting balance amount to zero over n years and m days assuming interest rate x. Withdrawals and interest happen annually. The first withdrawal happens right away and is subject to no interest, the twist comes with the second withdrawal which happens after m days which would be a partial years worth of interest (if m is not 365), and the withdrawals thereafter happen annually. Partial year interest rate would be calculated as (1+i)^(m/365).

Is there a single formula or combination of formulas I can use that will give me the level withdrawal amount if I know the initial amount, the interest rate and the number of years and days?