Md. Code Ann., Tax-Gen. § 10-603
Unless an act that changes the State income tax rate provides otherwise, if the rate changes on a date other than the 1st day of the taxable year of a person, the person shall compute State income tax using the tax rate that applies to each part of the year.
Added by Acts 1988, c. 2, § 1, eff. Jan. 1, 1989.
Formerly Art. 81, § 285.