A.D., at the moment no one knows,
There has been a wide divergent of dates in the past for the filming dates for a spring edition of TAR, it's really hard to speculate unless there's something tangible that shows that TPTB have moved forward towards filming. Sometimes, it's an announced application period for a particular edition, aometimes, it has been an item in the entertainment industry trade news media, sometimes CBS actually puts something out.
We're all just as anxious to know as you are, believe me. But patience is as much a virtue in race detective work as it is for a Racer while Racing.