In all school districts of the first class and first class A, the fiscal year shall begin on the first day of January in each year: Provided, That the Board of Public Education of any district of the first class or first class A may, by resolution adopted by two-thirds vote of the members thereof at a meeting of the board after not less than ten days' notice of the fact that such resolution would be presented for action at such meeting, fix the fiscal year of such school district so as to begin on the first day of July in each year instead of on the first day of January as hereinabove provided.