Section 151(1) in The U.P. Municipalities Act, 1916
(1)In a [municipal area] [Substituted by U.P. Act No. 12 of 1994.] other than one situated wholly or partly in a hilly tract, when a building or land has remained vacant and unproductive of rent for ninety or more consecutive days during any year the [Municipality] [Substituted by U.P. Act No. 12 of 1994.] shall remit or refund so much of the tax of that year as may be proportionate to the number of days that the said building or land has remained vacant and unproductive of rent.