Is there a time limit on interpousal transfer deed?

My ex and I (bifurcated divorce) want to create an agreement that allows for a interspousal tansfer of a property at a later date with exchange of money at that time (when it is logistically possible) as part of the settlement to avoid taxes. Is there a time limit for such a transfer? Does the time limit need to be spelled out in the agreement? Does the compensation amount need to be fixed for this to be considered part of the settlement? We live in California and have two homes both as JTRS. The agreement would call for one (free and clear) to be transferred immediately to my ex and the other which has an encumbrance in both names would initially be transferred to me (if that is possible with encumbrance) and later transferred to my ex when feasible.