The tide, or depth of the ocean near the shore, changes throughout the day. The depth of the bay can be modeled by d = 35 - 28 cos (π/6.2 t)
where d is the depth in feet and t is the time in hours. Consider a day in which t = 0 represents 12:00 A.M. At what time is the water depth 8.5 feet. (Round to the whole number)