Post dating a legal form
If the document is putting in place something which “should have been done” but hasn’t been, usually for tax or similar reasons, then the position is straightforward.
For example, if a seller had sold his house in December then the seller could have taken advantage of certain tax benefits.
To deal with this problem, you could adjust my recommended dated-signatures boilerplate by adding the sentence in bold italics: 14. This agreement will become effective when all the parties have signed it.
The date this agreement is signed by the last party to sign it (as indicated by the date associated with that party’s signature) will be deemed the date of this agreement.
Designating one party in this manner would only work if one party is responsible for transaction logistics. The date this agreement is signed by the second party to sign it (as indicated by the date associated with that party’s signature) will be deemed the date of this agreement.
He also has no way of knowing whether the backdating will be scrutinized by a regulatory authority or even a Court.
Or they sign and date the contract but wait a few days before returning it?
In either case, the result could be that the contract is given a date that is different from the date that would have been used if the person signing had put in the actual date and promptly returned the signature page.
Is it legal to comply with the request or must it always be refused outright?
Alternatively, is there a way of legally trying to achieve the required objective?