The following fiscal years shall be established for educational service districts and shall apply to all governmental, proprietary, and fiduciary fund entities, including all account groups under the jurisdiction of the educational service district board of directors:

There shall be a twelve-month fiscal period of July 1, 1990, through June 30, 1991, for the 1990-1991 fiscal year.

For July and August 1991 there shall be a two-month fiscal period with a budget for this two-month period to be prepared by May 10, 1991.

For fiscal year 1991-1992 there shall be a twelve-month fiscal period beginning September 1, 1991, and ending on August 31, 1992, with a budget to be prepared by July 10, 1991.

For every fiscal year thereafter, a twelve-month fiscal period shall begin on September 1 and end on August 31 with an annual budget to be prepared by July 10th.