From a pure technical perspective it is possible to write AL code that does what you are asking for.
But it is not recommend and if you do not remember to update also all the related data and transactions you will easily break the consistency of your database.
In some regions it will also be in breach with regulations to do such a change.
The best practice and recommended way is to reverse the creditmemo then post a new creditmemo on the new date.
And if for any reason there is something in your data you think you can not correct with transactions you should discuss it with your partner so you can find a safe way to correct your data.