GSTR-3B filing deadlines require electronic submission and ledger-based discharge of tax liabilities by the prescribed due date. The State prescribes last dates for furnishing monthly returns in FORM GSTR-3B through the common portal for specified months and requires registered persons to discharge tax, interest, penalty, fees or other amounts payable by debiting the electronic cash ledger or electronic credit ledger, as applicable, not later than the prescribed last date for the return.