Utah Code § 68-3-7: Time, how computed.

(1) A person shall compute the period of time provided by law to perform an act by:

(a) excluding the first day; and

(b) except as provided in Subsection (2), including the last day.

(2) If the last day is a legal holiday, a Saturday, or a Sunday, then a person shall:

(a) exclude the day described in this Subsection (2) from the time computation described in Subsection (1); and

(b) compute the period of time to include the end of the next day that is not a legal holiday, a Saturday, or a Sunday.