From: utzoo!decvax!harpo!utah-cs!utah-gr!thomas
Newsgroups: net.unix-wizards
Title: Re: length of day
Article-I.D.: utah-gr.621
Posted: Fri Nov  5 10:45:08 1982
Received: Sat Nov  6 03:37:26 1982
References: cca.3362

Once and for all:
	The 'sidereal day' is 23 hours, 56 minutes, and 4 seconds.  This is
the period of the Earth's rotation with respect to the Universe (whatever that
means).
	The 'mean solar day' is 24 hours exactly (with the exception of those
leap seconds, which get stuck in because the second is defined relative to the
mean solar day of 1900, and the day is slowly lengthening).

Is that clear?

=Spencer