I think something has got lost in the translation.
rule five reads ;-
The delivery date should be fixed, if not, the goods have to be delivered at least 12 hours after the end of the auction. The contract has also to be signed 12 hours after it has been sent. If there is no time or money for signing the contract, this has to be negotiated with the seller.
Should it read;-
The delivery date should be fixed, if not, the goods have to be delivered within 12 hours of the end of the auction. The contract has also to be signed within 12 hours of it being sent. If there is no time or money for signing the contract, this has to be negotiated with the seller.