I don't say "24 hour day", in that the convential scientific wisdom is that the Earth's rotation rate in slowing, and a solar day has gotten shorter down through time.
Uh, oops. if the rotation is slowing the day is longer.
And it is by the way. If my memory is right the day is a small number of hours longer than when the dinosaurs lived.
[This message has been edited by NosyNed, 09-20-2003]