Except as otherwise provided by law, the city council shall, by ordinance, fix the compensation of all city officers; but the compensation of any elective officer shall not be increased or diminished to take effect during the time for which any such officer was elected. The compensation of all city officers shall be paid monthly out of the treasury. The salaries of the elective officers shall be fixed by ordinance at the regular meeting of the city council during the month of October preceding the next municipal election, and biennially thereafter. (Prior code § 1-1-8)