Mont. Code Ann. § 1-1-301
1-1-301 Definitions
1-1-301 . Definitions. Unless the context requires otherwise, the following definitions apply in the Montana Code Annotated:
(1) A "day" is the period of time between any midnight and the midnight following.
(2) "Daytime" is the period of time between sunrise and sunset, and "nighttime" is the period of time between sunset and sunrise.
(3) "Month" means a calendar month.
(4) A "week" consists of 7 consecutive days.
(5) "Year" means a calendar year.