Whenever any act of a secular nature other than a work of necessity or mercy is appointed by law or contract to be performed upon a particular day, which day falls upon a Sunday or holiday, the act may be performed upon the next business day with the same effect as if it had been performed upon the appointed day. When so provided by the rules of court, the act also may be performed upon the next business day with the same effect as if it had been performed upon the appointed day if the appointed day falls on a Saturday.