books.google.com - What would life be like with no clocks and no calendars? How would you know when to get up in the morning? How would you know when baseball season was about to start?. Long, long ago, all people could do was watch the sun and moon and try to figure things out. Eventually they made simple clocks like...http://books.google.com/books/about/How_Do_You_Know_What_Time_It_Is.html?id=RddtfR52OLAC&utm_source=gb-gplus-shareHow Do You Know What Time It Is?