Mike Shaw wrote:
(snip)
I have always had concerns with the EofT when it does not take into account
the distance from the standard meridian - to the uninitiated, the dial STILL
doesn't give "clock" time, reinforcing their (incorrect) opinion that
sundials
don't work properly.
If I include an EofT graph or table for a known location, I add (or
subtract) the longitude
correction.
(snip)
I agree with Mike. It seems sensible to offer a total correction to
apply to dial time to get clock time, for people often ask, after
viewing a sundial, "But what time is it really?" Less often do they
look at a clock and wonder what the sundial shows. (And that's
fortunate, for around here a sundial is typically illuminated by the
sun perhaps 15% of the 8766 or so hours of a year.)
My dials tend to be designed to show local apparent time, so I often
include a graph or table showing the total number of minutes which
should be added to dial time for clock time. For a sundial designed
for a location where daylight time is used, my graph or table gives
minutes to add to get daylight time. That makes the correction from
sundial time to daylight time such that there is no addition of
negative minutes (read subtraction), something difficult for lots of
folks where time is concerned. When daylight time is not in effect,
simply knock off an hour.
Mac Oglesby
