Find last occurrence in an array

Hello!

I have a list of dates and account balances. I want to retrieve the balance of the last day of each month. The last day on the list is not always the last day of the month because we don't work every single day, and I don't want to add rows to the spreadsheet. I have added helper columns B, C, D, and H, that could be hidden or deleted if not needed. I was not able to match the years and months with the last day of the month on the list and return the balance, using combinations of index, match, lookup, etc.

What formula do I write in J2:L13 to return the last balance on each month?

Thank you!