On 11.09.13 10:56, Paul Eggert wrote:
Thanks for looking into that. It confirms that Bern time was not exactly GMT+0:30, though we still don't know what it was; our current value (derived from one of the Shanks values) is probably wrong by a few seconds. It also confirms my suspicion that the 1894 transition was messy, but it suggests that our 1894 transition date of June 1 is correct for Zurich, as my guess is that Zurich was not one of the recalcitrant cantons (though it'd be nice to confirm this).
Shanks gives Bern time meridian as 7°26' which is (because he is never more precise than minutes of arc) as close as he can get to the coordinates of the old Bern observatory, which are also the base point of Swiss country topography (Fundamenalpunkt der Schweizer Landeskoordinaten). The Federal regulations say http://www.admin.ch/opc/de/classified-compilation/20071096/index.html Der Fundamentalpunkt im Meridianzentrum der alten Sternwarte von Bern hat die ellipsoidische Länge l = 7°26'22.50" und die ellipsoidische Breite j = 46°57'08.66". I.e. the meridian for Bern mean time, which was based on this observatory, is 7°26'22.50" Expressed in time, it is 0h29m45.5s
It'd also be helpful to know what time of day the 1894 transition was; we're currently guessing 00:00.
I guess so as well. Lacking other information, it seems sensible to assume a change of time