Changing contract, what start date?

[SJ35]

Hi,
Probably a stupid question but as a parent has changed days and we have both moved house I am writing a new contract. Do I put the original start date on it with the original deposit? Or the new start date with no deposit taken?
Confuzzled!!

Thanks xx

[Bakez66]

I've just attached my new address to the contract and got the parents to sign it, and wrote down the date i moved, I also gave them a copy which they stapled to theirs then for change of hours I've attached a letter stating it's an extension of the original contract and included new days/ times and got parents to sign it.