Cal. Probate Code § 6111

(a) A will that does not comply with Section 6110 is valid as a holographic will, whether or not witnessed, if the signature and the material provisions are in the handwriting of the testator. (b) If a holographic will does not contain a statement as to the date of its execution and: (1) If the omission results in doubt as to whether its provisions or the inconsistent provisions of another will are controlling, the holographic will is invalid to the extent of the inconsistency unless the time of its execution is established to be after the date of execution of the other will. (2) If it is established that the testator lacked testamentary capacity at any time during which the will might have been executed, the will is invalid unless it is established that it was executed at a time when the testator had testamentary capacity. (c) Any statement of testamentary intent contained in a holographic will may be set forth either in the testator’s own handwriting or as part of a commercially printed form will.