Md. Code, Local Government § 20–103

(a) In this section, “legal holiday” means:

(1) the day on which a legal holiday, as defined under § 1–111 of the

General Provisions Article, is observed; or

(2) a federal legal holiday.

(b) Notwithstanding any other law, when the last day to pay a tax, file a tax

return, or perform any other act that relates to taxes under this title falls on a

Saturday, Sunday, or legal holiday, performance of the act is timely if the act is

performed on the next succeeding day that is not a Saturday, Sunday, or legal holiday.

(c) The last day to perform an act described under subsection (b) of this

section is the last day of any authorized extension of time.