Got this info today and thought it was useful from the Federal Rules of Civil Procedure. It deals with how "Next Day” is defined in FRCP 6(a)(5).
If your deadline is thirty days after an event (i.e. 20 days after a complaint is filed), and that date ends up on a weekend or holiday, your due date is the next business day counting forward (Monday, for example, if a weekend).
HOWEVER, if the deadline is thirty days before an event (i.e. thirty days prior to trial), you count backwards from the event and, if that date ends up on a weekend or holiday, your date is the next business day COUNTING BACKWARDS (that’s a Friday).