Except the year 1900, every fourth year which, by usage in this state, is considered a leap year is a leap year consisting of 366 days.
Mont. Code Ann. § 1-1-303, under Rules Concerning Time.
Mont. Code Ann. § 1-1-303
Except the year 1900, every fourth year which, by usage in this state, is considered a leap year is a leap year consisting of 366 days.