(a) If the governing body of the county elects to levy or impose any of the taxes herein authorized to be levied and imposed, it shall specify, as the effective date of such levy, the first day of any calendar month following such levy; provided that such governing body may not levy or impose any such taxes unless the effective date of such levy is at least 15 calendar days after the date of such levy, and is not less than 45 days nor more than 90 days after May 19, 1981. The maximum duration of the levy of any of the taxes herein authorized to be levied and imposed shall be a period of six years from the effective date of such levy, subject to earlier termination as follows:

(1) If any public building securities are hereafter issued, none of such taxes may be levied after the expiration of the sixth calendar month next following the month during which the last of such securities are paid and retired; or

(2) If no public building securities are hereafter issued and the governing body of the county instead elects to pay all the costs of the courthouse improvements and the justice center by accumulating moneys therefor, none of such taxes may be levied after (i) the last day of the calendar month during which moneys sufficient therefor have been accumulated, or (ii) the whichever of the foregoing (i) or (ii) occurs first.

(b) Any proceeds from the taxes herein authorized that are on hand at the time of the termination of the levy (or that are thereafter received) and that are not needed for payment of debt service on any public building securities shall be used to pay the costs of operating and maintaining the justice center.

(c) Nothing herein contained shall prohibit the governing body of the county, subject to constitutional limitations on the impairment of contracts, from reducing, at any time after the levy of any of the taxes herein authorized, the rate at which any of such taxes is levied or from ceasing to levy or impose any such taxes.