The 2nd Installment is due February 1, 2016, and becomes delinquent at close of business on April 11, 2016. Whenever the delinquent date (normally April 10th for 2nd installment) falls on the weekend, taxpayers have until the following business day to pay the taxes without penalty. Only U.S. Postmark is observed. Office hours are 8:00 AM to 5:00 PM, Monday-Friday, except holidays.