A tremendous discovery began to poke its nose above the edge of their familiar world. But they could not pull it up far enough to "see" as yet. Uncle Felix continued to pull it up for them. That he, too, was muddled never once occurred to them. "Scientific men, like all other people, are not always to be relied upon," he went on. "They make mistakes like--you, or Thompson, or Mrs. Horton, or--or even me. Clocks, we all know, are full of mistakes, and for ever going wrong. But the same thing has happened to calendars as well. Calendars are notoriously inaccurate; they simply cannot be depended upon. No calendar has ever been entirely veracious, nor ever will be. Like elastic, they are sometimes too long and sometimes too short--imperfectly constructed." He paused and looked at them. "Yes," they said breathlessly, aware dimly that accustomed foundations were already sliding from beneath their feet. "Half the calendars of the world are simply wrong," he continued, more boldly still, "and the people who live by them are in a muddle consequently--a muddle about Time. England is no exception to the rest. Is it any wonder that Time bothers us in the way it does--always time to do this, or time to do that, or not time enough to finish, and so on?" "No," they said promptly, "it isn't." "Of course," he resumed. "Well, sometimes a nation finds out its mistake and alters its calendar. Russia has done this; the Russian New Year and Easter are not the same as ours. Pope Gregory, the thirteenth, ordered that the day after October 4, 1582, should be called October 15. He called it the Gregorian Calendar; but there are lots of other calendars besides--there's the Jewish and Mohammedan, and a variety of calendars in the East. All of them can't be right. The result is that none of them are right, and the world is in confusion. Some calendars mark off too many days, others mark off too few. Half the world is ahead of Time, and the other half behind it. The Governments know this quite well, but they dare not say anything, because their officials are muddled enough as it is. There is everywhere this fearful rush and hurry to keep up with Time. All are terrified of being late--too late or too early." "Naturally." "And the extraordinary result of all these mistakes," he went on marvellously, "is simply this: that a considerable amount of Time has never been recorded at all by any of them. There are a lot of extra days, unused, unrecorded days, still at large--if only we could find them." "Extra Days!" they gasped. Tim and Judy's mouths were open now, and slowly opening wider every minute. Only Maria's mouth kept closed. Her great blue eyes were closed as well. She looked as if she could have told them all this in a couple of words!