Re: Gordon's assertion that there is an error in encarta's statement "The difference in the length of the 24-hr day at different seasons of the year can amount to as much as 16 min." I'm no expert on equation of time, but perhaps they are refering to the fact that at perihelion the increase in Earth's speed of revolution would cause the day time to appear shorter (though the sideral day is of course the same)/the reverse at aphelion. Anyway I'll leave further comments to people with more knowledge than I. (16 minutes sounds about right to me though)
Troy Heck.
