All public officers holding office at the date of the approval of said amendments,--not otherwise provided for,--whose terms of office expire at any time during an odd-numbered year, shall continue to hold their offices until the first Monday of January in the next even-numbered year; and that all such officers whose terms expire in an even-numbered year shall continue to hold their offices until the first Monday of January in the next even-numbered year.
65 P.S. § 71