[tz] [PROPOSED] Sub-second history for Maputo and Zurich

[Paul Eggert]

On 2024-05-24 16:29, Steve Allen via tz wrote:
> I urge great caution for the use of subsecond offsets.

Yes, and even offsets with one-second precision are dicey for older 
civil time; see, for example, the comments in 'europe' about Dunsink 
Mean Time. The subsecond offsets are put in mostly just to document the 
legal or announced definition of local time.

Come to think of it, it's not entirely clear that Bern Mean Time legally 
corresponded to 7° 26' 22.50". The source for that meridian is here:

https://www.admin.ch/opc/de/classified-compilation/20071096/index.html

but this comes from government publications dated May 2008. It'd be 
better to cite a source for BMT during the period 1853 to 1894 when it 
was actually being observed.


 From the point of view of TZif files the subsecond offsets are all 
trivia, since the subsecond info doesn't affect them.