corrected DST data Switzerland 1941 and 1942, final report

Alois Treindl alois at
Thu Dec 18 00:43:27 UTC 2008

Paul Eggert wrote:

> By the way, was Bern Mean Time actually exactly 29 minutes and 44
> seconds ahead of GMT?  Our only source for that is Shanks.

I have not seen an official document yet which defines the Swiss time
standard of 1854 - 1894. Maybe I will make another trip to the Zurich
central library to check the law collection.

Traditionally the locations of astronomical oberservatories were used as
reference point. The 'Alte Sternwarte Bern' (old Bern observatory) was
used as the reference point for the national swiss geodetic system of 1903,

Its location is given in as
Latitude = 46° 57' 08.66" geogr. Breite des Nullpunkts in Bern (**)
Longitude = 7° 26' 22.50" geogr. Länge des Nullpunkts in Bern (**)

This longitude converted to time gives 29m45.5s which is 1.5 seconds off
the Shanks value. As far as I know Thomas Shanks (whom I personally met
in 1987) has always second values which are a multiple of 4, and I
presume this comes from the fact that he rounded longitude to integer
minutes. He gives as longitude of Bern 7°26' and therefore arrives at

|| Alois Treindl,  Astrodienst AG,  mailto:alois at
|| Zollikon/Zurich, Switzerland
|| Free astrological charts at
|| SWISS EPHEMERIS Free Edition at

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