Alien: Earth /tt13623632/

This series premieres tonight on FX, but when I go to add a new release date for its TV premiere, all I get are "no change" and "correct/delete" options. Why is that? From TV Guides' TV grid (CDT): 1129 FXHD Alien: Earth 7:00 PM - 8:32 PM Premiere Alien: Earth 8:32 PM - 9:50 PM New Alien: Earth 9:50 PM - 11:22 PM Alien: Earth 11:22 PM - 12:41 AM