Time of supply of services establishes when tax liability arises, based on invoice, payment, provision, or accounting entry. Time of supply of services fixes tax liability at the earliest applicable event: where invoice is timely, the earlier of invoice date or receipt of payment; where invoice is not timely, the earlier of provision date or receipt of payment; otherwise the date the recipient records the service. Reverse charge supplies are timed by recipient payment or a date following sixty days from supplier's invoice with accounting-entry fallbacks and a special rule for supplies from associated enterprises outside India. Voucher supplies and value additions by interest or penalty have their own specified timing rules.