Cal. Family Code § 6500 : California Family Code — Minors — Minor defined; calculation of period of minority Date: 7 Sep 2016 TEXT PDF Current through the 2016 Legislative Session A minor is an individual who is under 18 years of age. The period of minority is calculated from the first minute of the day on which the individual is born to the same minute of the corresponding day completing the period of minority. Ca. Fam. Code § 6500