Fort Worth Zoo Hours: The zoo is open 365 days per year. From October 29, 2012 to February 15, 2013 the zoo’s opening hours are from 10:00 a.m. to 4:00 p.m. From February 16, 2013 to March 22, 2013 the zoo’s opening hours are from 10:00 a.m. to 5:00 p.m.