California Code, Probate Code - PROB § 15001

(a) This division applies to all trusts regardless of whether they were created before, on, or after July 1, 1987.

(b) This division applies to all proceedings concerning trusts commenced on or after July 1, 1987.

(c) This division applies to all proceedings concerning trusts commenced before July 1, 1987, unless in the opinion of the court application of a particular provision of this division would substantially interfere with the effective conduct of the proceedings or the rights of the parties and other interested persons, in which case the particular provision of this division does not apply and prior law applies.