ratus and appurtenances shall be removed from the premises the next day following the closing of the carnival. (6) The hours of such operation to be limited between the hours of 10:00 a.m. and 10:00 p.m. 8. Occasional Use of Private Homes for Adult Education Classes. (Added by Ord. No. 132,573, Eff. 8/5/66.) — Notwithstanding any provision of this article to the contrary, adult education classes shall be permitted in homes in the RA or R Zones and no additional off-street parking shall be required in conjunction therewith, provided that: (a) Classes are held not more than one day a week for a period not to exceed three hours per day end each class does not meet for more than fifteen weeks in any one semester. (b) Classes are purely incidental to the use of the property as a home and no more than thirty persons are permitted to attend each class. (c) Classes primarily involve oral discussions and no laboratory equipment, heavy machinery, or large tools are used in connection therewith, except small record players, slide projectors and other similar audiovisual teaching aids. (d) All classes are scheduled on the first floor of the building. For the purpose of this subdivision “ adult education classes ” shall mean any educational programs conducted by University Extension of University of California or any other comparable university. No certificate of occupancy shall be required in connection with the use authorized by this ordinance. 9. Maintenance of Accessory Structures. (Amended by Ord. No. 172,839, Eff. 11/1/99.) Notwithstanding any provisions of this article to the contrary, an accessory building or structure may be maintained on a lot without a main building and a residential building may be maintained on a lot without the required off-street parking for the periods of time as authorized by the Advisory Agency in conformance with Article 7 of Chapter 1 of this Code. 10. Model. (Amended by Ord. No. 174,999, Eff.