Article 13

When the laws speak of years, months, days or nights, it shall be understood that years are of three hundred sixty-five days each; months, of thirty days; days, of twenty-four hours; and nights from sunset to sunrise.

If months are designated by their name, they shall be computed by the number of days which they respectively have.

In computing a period, the first day shall be excluded, and the last day included. (7a)