California Code, Education Code - EDC § 46147

Notwithstanding the 180-minute minimum day requirement of Section 46144, the governing board of any school district may permit a 12th-grade pupil in his or her last semester or quarter, as the case may be, before graduation, who is enrolled in a work experience education program approved under the provisions of Article 7 (commencing with Section 51760) of Chapter 5 of Part 28 and who would complete all of the requirements for graduation by attending high school, except courses of physical education, for less than 180 minutes each day, to attend high school for less than a minimum day of 180 minutes, upon the written request of a parent or legal guardian or upon his or her own request if the pupil is 18 years of age or over.  If a pupil attends classes for less than 180 minutes per day pursuant to this section, the number of minutes actually attended per day shall be rounded down to the nearest multiple of 60.  The average daily attendance allowed for that pupil's attendance shall bear the same proportion to one day of attendance as the number of minutes of attendance per day bears to 180.