N.H. Rev. Stat. Ann. § 21:7

The words "biennial" and "biennially," when applied to meetings and elections in towns, shall mean the biennial meetings and elections required by law to be holden in the month of November biennially, dating from the commencement of biennial elections in 1878; and the word "annual," when applied to meetings and elections in towns, shall mean the annual meetings and elections required by law to be holden in the month of March.