Utah Code § 10-20-1104

(1) The municipality shall enact an ordinance establishing a reasonable time of not less than 10 days to appeal to an appeal authority a written decision issued by a land use authority. (2) In the absence of an ordinance establishing a reasonable time to appeal, a land use applicant or adversely affected party shall have 10 calendar days to appeal to an appeal authority a written decision issued by a land use authority. (3) Notwithstanding Subsections (1) and (2), for an appeal from a decision of a historic preservation authority regarding a land use application, the land use applicant may appeal the decision within 30 days after the day on which the historic preservation authority issues a written decision.