Sum the same cell across the sheets in Google Sheets

Question

I have a sheet for every day in the month. At the end of every month, I need to sum the same cell across all tabs. The following works:

=SUM(March31!L2,March30!L2,March29!L2,March28!L2,March26!L2,March25!L2,March24!L2)

However, at the end of the month, the formula will be tremendous. Tried the following:

=SUM(March31:March1!L2)

Doesn't work. Is it even possible?

Answer 1

SUM(March31:March1!L2)

that won't work, but you can use kind of a generator:

={" "; ARRAYFORMULA("=SUM("&TEXTJOIN(", ", 1, TEXT(ROW(INDIRECT(
 DATEVALUE("2020/01/01")&":"&DATEVALUE("2020/12/31"))), "mmmmd!L2"))&")")}

which will give you the full formula you need, so all you need to do is copy-paste the cell below:

spreadsheet demo