The head of each budget unit, not later than July fifteenth of each year next preceding the session of the legislative assembly, shall submit to the office of the budget, estimates of financial requirements of the person‘s budget unit for the next two fiscal years, on the forms and in the manner prescribed by the office of the budget, with such explanatory data as is required by the office of the budget and such additional data as the head of the budget unit wishes to submit. The estimates of financial requirements for budget units under the control of the state board of higher education must be made using the same forms, supporting information, and documentation as other budget units. Any request for a new full-time or part-time permanent position included in a budget unit’s estimate of its financial requirements for the next two fiscal years must include documentation justifying the need for the position. The documentation must describe the circumstances resulting in the need for the position and identify the number of hours the position will be involved in specific types of activities and the anticipated outcomes of the activities. The estimates so submitted must bear the approval of the board or commission of each budget unit for which a board or commission is constituted. The director of the budget may extend the filing date for any budget unit if the director finds there is some circumstance that makes it advantageous to authorize the extension. If a budget unit has not submitted its estimate of financial requirements by the required date or within a period of extension set by the director of the budget, the director of the budget shall prepare the budget unit’s estimate of financial requirements except the estimate may not exceed ninety percent of the budget unit’s previous biennial appropriation. The director of the budget or a subordinate officer as the director shall designate shall examine the estimates and shall afford to the heads of budget units reasonable opportunity for explanation in regard thereto and, when requested, shall grant to the heads of budget units a hearing thereon which must be open to the public.