Neb. Rev. Stat. §§ 32-405
Any special election under the Election Act shall be held on the first Tuesday following the second Monday of the selected month unless otherwise specifically provided. Except as otherwise specifically provided, no special election shall be held under the Election Act in April, May, June, October, November, or December of an even-numbered year unless it is held in conjunction with the statewide primary or general election. No special election shall be held under the Election Act in September of an even-numbered year except as provided in section 32-564 and except for a special election by a political subdivision pursuant to section 13-519 or 77-3444 to approve a property tax levy or exceed a property tax levy limitation. A special election for a Class I, II, III, IV, or V school district which is located in whole or in part in a county in which a city of the primary or metropolitan class is located may be held in conjunction with the primary or general election for a city of the primary or metropolitan class which is governed by a home rule charter.
Neb. Rev. Stat. §§ 32-405