Time of supply of goods determines tax liability by the earliest of removal, invoice, payment, or recipient book entry. The time of supply of goods is the earliest of: removal/making goods available, invoice issuance, payment receipt, or recipient's book entry. For immovable, assembled, installed, or agent-supplied goods, 'made available' means placed at recipient's disposal. Continuous supplies use the expiry of the period covered by successive statements or payments, or otherwise invoice/payment date; specified supplies can be notified as continuous. For reverse charge, time is earliest of receipt, payment, invoice receipt, or debit. Goods on approval are taxed when supply is confirmed or six months after removal. If indeterminate, time is return due date or tax payment date.