What time is it? This lecture is the first part of a two-part

exploration of the astronomical origins of our time-keeping and calendar

conventions. Today we will discuss the division of the year into

seasons by the motions of the Sun, and the oft-forgotten origins of our

holidays in in the solar Quarter and Cross-Quarter days, the division of

the year into 12 months based approximately on the cycle of lunar

phases, the traditional division of the month into weeks reflecting the

seven moving celestial bodies, and the division of the day into hours,

minutes, and seconds. We will also discuss the difference between the

Solar and Sidereal days, and the introduction of timezones used in modern

civil timekeeping. Recorded 2006 Oct 3 in 100 Stillman Hall on the

Columbus campus of The Ohio State University.