A cell formula can only act on the cell that contains it.
You could write (possibly nested) IF formulas in each cell, but your post
provided too little information about the sheet layout for specifics. As a
starting point, a monthly cell might contain something like
Instead of writing formulas in each cell, another approach would write a VBA
macro that would populate the relevant cells, but that is a more advanced
topic than is likely wanted in a newusers' post.