Except as provided in subsection (b) of this section, in computing the time under this article for performing an act, Saturdays, Sundays, and legal holidays shall be included. In a computation of time under this article, the day of performing an act and the day of registration or election shall be excluded. If a computation of time would require an act to be performed on a Saturday, Sunday, or legal holiday, the act shall be performed on the next regular business day following that Saturday, Sunday, or legal holiday.