The value date is the date when the interest is calculated. The interest is not yours, but the interest generated by the transfer of positions between banks.

Because although your money is given to the bank, the bank can't send your money abroad directly. You have to adjust your deposit in a foreign bank to realize international remittance, that is, you give your deposit abroad to your payee. The increase or decrease of deposits naturally involves interest, because deposits between banks also have interest.