Return filing deadlines for FORM GSTR-3B set; tax liabilities must be discharged via electronic cash or credit ledgers. The Commissioner prescribes last dates for furnishing FORM GSTR-3B electronically through the common portal for specified months, and mandates that registered persons 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 filing the return.