GSTR-3B filing deadlines set for months; tax liabilities must be discharged via electronic cash or credit ledger by dates. Specification of deadlines for furnishing the return in FORM GSTR-3B for August 2017 through December 2017, to be filed electronically through the common portal on or before the dates in the Table. Registered persons furnishing FORM GSTR-3B must discharge tax, interest, penalty, fee or other amounts payable under the Act by debiting the electronic cash ledger or electronic credit ledger, as applicable, not later than the corresponding last date for filing.