Re: bootstrap from scratch

[Ed Reingold]

> Perhaps it would be better to set `calendar-latitude' to 51.5 and
> `calendar-longitude' to 0.0 by default but then tell people who want
> to learn about solar and lunar times that that default location is for
> Greenwich, England.  That info should go away if `calendar-latitude'
> and `calendar-longitude' are set to any other value.

Still a bad idea, for the same reason: Emacs will display times of solar and 
lunar phenomena that are wrong, but subtly so.  The only default value must be 
nil so that any calculations are trapped.

This is a conundrum: Any value that lets the compilation proceed will 
(necessarily) produce wrong results.  Any value that stops the calculation if 
the latitude/longitude/zone are not set will stop compilation.  Silly.