SCHOOLS — DAYS REQUIRED TO BE IN SESSION — DAYS FOR PROFESSIONAL MEETINGS Pursuant to 70 Ohio St. 1-109 [70-1-109] (1971), it is mandatory that school be in session and instruction offered for not less than one hundred eighty (180) days, provided that said one hundred eighty (180) days may be reduced by up to, but not to exceed, five (5) days used for attendance of professional meetings. The Attorney General has considered your request for an opinion, wherein you refer to 70 Ohio St. 1-109 [70-1-109] (1971), and ask the following question: "Based upon the above statute, 'Does a school system have to be in session and instruction offer sic and students in class for at least 180 days or 175 days.' " Title 70 Ohio St. 1-109 [70-1-109] (1971) provides as follows: "A school year for all public schools in Oklahoma shall consist of at least ten (10) months of four (4) weeks each, of which time school shall actually be in session and instruction offered for not less than one hundred eighty (180) days. Provided, however, five (5) days may be used for attendance of professional meetings and teachers may be paid for a length of term in excess thereof, under conditions hereinafter outlined. A school district may maintain school for less than a full term only when conditions beyond the control of school authorities make impossible the maintenance of said term." By a plain reading of the above statute, "school shall actually be in session and instruction offered for not less than one hundred eighty (180) days." In the construction of statutes, the word "shall" is usually interpreted as implying a command or mandate. Oklahoma Alcoholic Beverage Control Board v. Moss, Okl., 509 P.2d 666, 668 (1973). Thus, the number of days that school is to be in session and instruction offered is mandatory. The minimum number of days that school is to be in session and instruction offered is one hundred eighty (180) days. However, five (5) days of the said one hundred eighty (180) days may be used for attendance of professional meetings. The length of a school session and the time allowed therefrom for professional meetings is further set out at 70 Ohio St. 1-110 [70-1-110] (1971), which provides, in part, as follows: ". . . No holiday or other occasion when school is not in session shall be included in the one hundred eighty (180) days required to be taught, except not to exceed five (5) days may be used for attendance of professional meetings. . . ." Pursuant to the foregoing, it is mandatory that school be in session and instruction offered for not less than one hundred eighty (180) days, provided that up to, but not to exceed, five (5) days of the said one hundred eighty (180) days may be used for attendance of professional meetings. Accordingly, the required one hundred eighty (180) days may thereby be reduced by up to five (5) days used for attendance of professional meetings, but in no event to less than one hundred seventy-five (175) days. The language of 70 Ohio St. 1-109 [70-1-109] (1971) is plain and unambiguous and its meaning clear. Therefore, said section must be accorded the meaning as expressed by the language therein. General Motors Corporation, Argonaut Division v. Cook, Okl., 528 P.2d 1110, 1114 (1974). It is, therefore, the opinion of the Attorney General that your question be answered as follows: Pursuant to 70 Ohio St. 1-109 [70-1-109] (1971), it is mandatory that school be in session and instruction offered for not less than one hundred eighty (180) days, provided that said one hundred eighty (180) days may be reduced by up to, but not to exceed, five (5) days used for attendance of professional meetings. (HAROLD B. McMILLAN, JR.) (ksg)