The time limit for seeking judicial review of agency action is thirty days. Iowa Code § 17A.19(3). In the alternative, a party may seek rehearing before the agency pursuant to Iowa Code § 17A.16(2). the application for rehearing must be filed within twenty days of the agency's final decision. Judicial review of a refusal to allow rehearing must be sought within thirty days of the date on which the application is denied or deemed denied. Iowa Code § 17A.19(3).