What is Filed on, and why does it matter?

The day a return was filed on the GST or TRACES portal, as its acknowledgement shows. Record what the CA filed and Mark filed both ask for it. It starts at today's date, and it can't be in the future, or before the month (for a TDS return, the quarter) ends: for September's GSTR-3B, the earliest is 30 September.

It matters because the GST and TDS returns record Margin sends to Galley works out from it whether each return was filed on time or late. Lenders and investors read that record, so use the day on the acknowledgement, not the day you record it.