807. Time of disposal and acquisition where asset disposed of under contract.

When an asset is disposed of and acquired under a contract1, the time at which the disposal and acquisition is made is the time the contract is made and not, if different, the time at which the asset is conveyed or transferred2. If the parties purport to vary the contract, the variation may amount to a discharge of the old contract and the making of a new one. Where this happens, the disposal is under the new contract, and the purported variation is therefore the date of disposal