There was another pause, and then Madam Bones’s voice said, “I have information which I learned four hours into the future, Albus. Do you still want it?”
Albus paused -
(weighing, Minerva knew, the possibility that he might want to go back more than two hours from this instant; for you couldn’t send information further back in time than six hours, not through any chain of Time-Turners)
McGonagall thinks so, at least: