On or before the second Monday of the fourth month prior to the beginning of the city's next fiscal year, or at such other time as the city may provide by ordinance or charter, the clerk shall notify in writing the head of each department of a code city to file with the clerk within fourteen days of the receipt of such notification, detailed estimates of the probable revenue from sources other than ad valorem taxation and of all expenditures required by his or her department for the ensuing fiscal year. The notice shall be accompanied by the proper forms provided by the clerk, prepared in accordance with the requirements and classification established by the state auditor. The clerk shall prepare the estimates for interest and debt redemption requirements and all other estimates, the preparation of which falls properly within the duties of his or her office. The chief administrative officers of the city shall submit to the clerk detailed estimates of all expenditures proposed to be financed from the proceeds of bonds or warrants not yet authorized, together with a statement of the proposed method of financing them. In the absence or disability of the official or person regularly in charge of a department, the duties herein required shall devolve upon the person next in charge of such department.