On or before 150 days prior to the commencement of the fiscal year, each township officer shall submit to the supervisor, or to the township superintendent if such officer has been appointed, an itemized estimate of the anticipated expenditures of the township for the next fiscal year for the township activities under his or her charge. The supervisor, or township superintendent, as the case may be, shall prepare a complete itemized budget proposal for the next fiscal year and shall submit it to the township board not later than 120 days prior to the commencement of the fiscal year.