Due dates · GST
GSTR-3B due date: monthly and QRMP calendar with late fee risk
GSTR-3B due dates for monthly filers and the QRMP scheme, how the 22nd and 24th state split works, interest and late fee for late filing, and where CBIC posts due-date changes.
Due dates · GST
GSTR-1 due date explained, with the GSTR-3B link
GSTR-1 due dates for monthly and QRMP filers, how the Invoice Furnishing Facility works, how GSTR-1 feeds GSTR-2B and GSTR-3B, and where CBIC posts extensions.
Due dates · Tax
ITR filing last date: due dates by taxpayer type and how to verify
The ITR filing last date depends on your taxpayer category under section 139(1). See the usual due dates for non-audit, audit, and company cases, how filing differs from verification, how CBDT extensions work, and how to confirm the date on official sources.