Oh, I absolutely believe animals can tell time! Ours knows exactly when it's time for lunch, for an afternoon walk, for dinner, and for an evening walk, and one last potty break before bedtime.
Of course, it could be because they know the routine! LOL!
I don't know...or maybe I do, because these cats are our barn kitties, and so on weekends the routine is different than during the school/work week. They show up at the door at very different times on weekends than they doo during the week.