1. General: Date on which a transaction actually takes place.
2. Accounting: Date on which allocated, budgeted, or contracted funds are paid, received, or used.
3. Banking: (1) Date on which an account holder can use the funds from deposited checks that have passed through the bank's clearing cycle. (2) date on which a deposit starts to earn interest.
4. Trading: Date on which the item that was bought or sold must be delivered.