[tz] TIme in Belize

[Paul Eggert]

On 11/7/20 9:58 PM, Steve Allen wrote:
> On Sat 2020-11-07T19:37:59-0800 Paul Eggert hath writ:
>> This says nothing about civil time observed in Belize city *before* 1912;
>> it's only an old-fashioned way to specify civil time in Belize *after* 1912.
> 
> I think a good avenue is to seek a library which has a complete
> collection of "The Honduras Almanack".

According to Google Books (which will not give me more than barely-readable 
snippets), page 56 of Volume 55 of the Boston Journal of Commerce and Textile 
Industries (1899) says "At Belize, British Honduras, the clock over the ??? 
????? which furnishes the time for the town, is usually regulated by the time 
kept by the ships in the harbor." This matches our guess earlier.

However, according to Google Books, the Report of the 8th International 
Geographic Congress (1904) contains a report by Lt Cmdr Edward Everett Hayden 
from the US Naval Observatory Time Service, which on page 795 says that Honduras 
(Belize) was 0h 52m 47s earlier than Washington Standard. Hayden cites "official 
reports received by the superintendent of the United States Naval Observatory, 
through the courtesy of the Department of State and of the Office of Naval 
Intelligence, Navy Department". This works out to -5:52:47, which is 1 second 
earlier from what we have now (-5:52:48), and which is 4 seconds later than the 
-5:52:43 that was being suggested from a reading of the 1927 ordinance. This 
also works out to 88° 11′ 45″ W, a longitude that goes through the heart of 
Belize city according to Google Maps. It's not clear where "ships in the harbor" 
were in those days; as Belize city is nearly surrounded by water I suppose they 
could have been at any of the longitudes discussed.

Our existing LMT of -5:52:48 comes from Shanks, which has only a 4-second 
precision in its local mean times. It'd be reasonable to change it to -5:52:47 
given the more-precise USNO source from 1904. Not sure it'd be as OK to change 
it to -5:52:43 which would put it about 200 m offshore to the east, according to 
the admittedly-imprecise Google Maps.