Service tax due dates and point of taxation rules govern collection, payment, and return filing timelines for taxpayers. Levy of service tax is triggered on provision or agreement to provide taxable services; the Point of Taxation Rules fix liability primarily at invoice issuance, with completion of service and advance receipts as alternative points. Eligible small taxpayers may elect receipt basis payment subject to turnover limits; others must pay on accrual basis. Quarterly payment cycles apply to eligible small taxpayers and monthly cycles to others, with electronic payment mandates. Returns and Cenvat credit statements are filed half-yearly; reverse charge and revised return provisions impose specific timing rules for payment and revision.