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Duplicates dates/months detected
Case 1 - Extra dates or extra sheets
This one is pretty straightforward. Either extra dates are in the spreadsheet somewhere on the same page but not inside the "normal" row of dates (like in the header, footer, or account name[s]) or else the user has accidentally included more than one sheet in the spreadsheets. In the latter case, you'll want to identify the "right" sheet in the document, and then just delete the others.