Below are some laws related to the time in British Honduras/Belize: Definition of Time Ordinance, 1927 (No.4 of 1927) [1927-04-01] Ordinances of British Honduras Passed in the Year 1927, p 19-20 https://books.google.com/books?id=LqEpAQAAMAAJ&pg=RA3-PA19 Definition of Time (Amendment) Ordinance, 1942 (No. 5 of 1942) [1942-06-27] Ordinances of British Honduras Passed in the Year 1942, p 31-32 https://books.google.com/books?id=h6MpAQAAMAAJ&pg=RA6-PA95-IA44 Definition of Time Ordinance, 1945 (No. 19 of 1945) [1945-12-15] Ordinances of British Honduras Passed in the Year 1945, p 49-50 https://books.google.com/books?id=xaMpAQAAMAAJ&pg=RA2-PP1 Definition of Time Ordinance, 1947 (No. 1 of 1947) [1947-03-11] Ordinances of British Honduras Passed in the Year 1947, p 1-2 https://books.google.com/books?id=xaMpAQAAMAAJ&pg=RA3-PA1 Time (Definition of) Ordinance (Chapter 180) The Laws of British Honduras in Force on the 15th Day of September, 1958 , Volume IV, p 2580 https://books.google.com/books?id=v5QpAQAAMAAJ&pg=PA2580 Time (Definition of) (Amendment) Ordinance, 1968 (No. 13 of 1968) [1968-08-03] https://books.google.com/books?id=xij7KEB_58wC&pg=RA1-PA428-IA9 Definition of Time Act (Chapter 339) Law of Belize, Revised Edition 2000 http://www.belizelaw.org/web/lawadmin/PDF%20files/cap339.pdf
Thanks again. I installed the attached patch to correct the older Belize data from Shanks. I left the 1973/1974 and 1982/1983 transitions from Shanks as-is, as we don't have citations for that period. I just now checked, and Chris Pearce's book "The Great Daylight Saving Time Controversy" (2017) also says that there were transitions in Belize in 1973/1974 and 1982/1983, though he gives no details about dates and times. Pearce also mentions British Honduras newspaper reports from the 1950s that agree with the legal citations you gave, so that's a good sign.
According to the 1942 Ordinance, it should be GMT-5 all year after 1942-06-27 midnight.
On 11/3/20 4:37 PM, P Chan wrote:
According to the 1942 Ordinance, it should be GMT-5 all year after 1942-06-27 midnight.
Thanks for catching that; I misinterpreted that ordinance. I installed the attached further patch. This uses the "CWT" / "CPT" abbreviations used elsewhere in North America, if only for consistency (I have no historical sources for the phrases or abbreviations actually used for Belize time during WWII).
On 11/6/20 1:59 PM, Michael H Deckers wrote:
-Zone America/Belize -5:52:48 - LMT 1912 Apr +Zone America/Belize -5:52:48 - LMT 1912 Apr 1
but the source is quite clear that it should be +Zone America/Belize -5:52:43 - LMT 1912 Apr 1
Unfortunately it's not so clear. Here's a citation to the source: # Definition of Time Ordinance, 1927 (No.4 of 1927) [1927-04-01] # Ordinances of British Honduras Passed in the Year 1927, p 19-20 # https://books.google.com/books?id=LqEpAQAAMAAJ&pg=RA3-PA19 It says that standard time was established as -06 on 1912-04-01, and that -06 was 00:07:17.27 later than the local mean time at Belize. However, by my calculations -05:52:42.73 is longitude 88° 10′ 40.95″ W, which Google Maps says is in the ocean east of Belize city, so this was not LMT in Belize city. To my mind what matters here is what was the legal time in Belize city before 1912-04-01. If there was no law or it was just LMT, no change needs to be made. If it was -05:52:42.73 then we need to find out when that legal time was instituted (perhaps for all of British Honduras?), and insert a transition from LMT to -05:52:42.73 at the appropriate date. One constraint we like to follow is that the LMT longitude corresponds to the longitude in zone1970.tab.
On 2020-11-07 08:18, Paul Eggert wrote:
Unfortunately it's not so clear.
Actually, I think it is quite clear: tzdb should record each official adjustment (step, discontinuity) of a clock indicating a local civil time scale. But tzdb should not (and in fact, it cannot) indicate the true deviation of a local civil time scale from UT or UTC, not only because the errors in the realizations of UTC or UT used by local time observatories are very hard to determine, but also because many of these deviations may consist in differences of rate versus UT or UTC or in steps of small sizes that could not be represented with tzdb data anyway. So the switch in the local civil time for Belize on 1912-04-01 was from T - 05:52:42.33 h to T - 06 h, where T is the realization of UT by the timing observatory for Belize at the time. And this is the fact that tzdb had to represent (possibly up to rounding). That T must have been off from UT by several seconds is also suggested by the telegraphy data of Milne, who reports that the Belize Court House clock was about UT - 05:52:47 h around 1899.)
One constraint we like to follow is that the LMT longitude corresponds to the longitude in zone1970.tab.
This is not mentioned as a constraint and is disliked in many cases. The modern geographic WGS-84 coordinates can be quite different from the astronomical coordinates assumed by a time observatory in a remote place around 1900, so I think it would not be helpful to add this constraint. Michael Deckers.
On Sat 2020-11-07T15:21:43+0000 Michael H Deckers via tz hath writ:
So the switch in the local civil time for Belize on 1912-04-01 was from T - 05:52:42.33 h to T - 06 h, where T is the realization of UT by the timing observatory for Belize at the time. And this is the fact that tzdb had to represent (possibly up to rounding). That T must have been off from UT by several seconds is also suggested by the telegraphy data of Milne, who reports that the Belize Court House clock was about UT - 05:52:47 h around 1899.)
The longitude of Belize in the 1787 map by William Faden had the coastline much farther west at longitude greater than 89 degrees. https://www.loc.gov/item/86692592/ The Roschshoof map from 1867 is closer to modern longitudes. https://www.loc.gov/resource/g4820.lh000157/ Ships with significant draft cannot approach Belize City, and it is plausible that the conventional time for Belize was set for a longitude off shore where the ships could anchor as contrasted with any point on the land itself. The 1912 record for the change in the time should be believed whether or not it corresponds to a longitude of a known place. -- Steve Allen <sla@ucolick.org> WGS-84 (GPS) UCO/Lick Observatory--ISB 260 Natural Sciences II, Room 165 Lat +36.99855 1156 High Street Voice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064 https://www.ucolick.org/~sla/ Hgt +250 m
On 11/7/20 2:24 PM, Steve Allen wrote:
Ships with significant draft cannot approach Belize City, and it is plausible that the conventional time for Belize was set for a longitude off shore where the ships could anchor as contrasted with any point on the land itself.
Yes, I agree that this is a plausible explanation, one that I also thought of. The question, though, is whether there was an official time in Belize city before 1912-04-01.
The 1912 record for the change in the time should be believed whether or not it corresponds to a longitude of a known place.
Also agreed, if it were a 1912 record but it's not; it's dated 1927, and says that local time was -06 from 1912 on, which means it doesn't address the issue at hand. Here's what the cited 1927 source says: "WHEREAS since the first day of April One thousand nine hundred and twelve the Standard Time adopted and observed in the Colony has been seven minutes, seventeen and twenty-seven hundredths seconds (7′ 17″.27) later than the local mean time at Belize and six hours later than Greenwich mean time :" 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. Possibly a Belize Mean Time was specified sometime before 1912, which established -05:52:42.73 as civil time throughout the city or even the colony. In that case, we could add a line switching from LMT to this time. We would need a source for this, though.
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". One copy from 1829 is widely found online, e.g. http://www.columbia.edu/cu/lweb/digital/collections/cul/texts/ldpd_8627122_0... That 1829 edition says that the Belize Meridian is longitude 88 deg 02 arcmin 00 arcsec. That location likely applies to a location in Fort George, and the WGS 84 longitude for the Fort George site is about 88 deg 10 arcmin 55 arcsec, so that gives a clock difference of over 30 seconds. If such a library exists then it should give clues for the evolution of the believed coordinates of Belize. -- Steve Allen <sla@ucolick.org> WGS-84 (GPS) UCO/Lick Observatory--ISB 260 Natural Sciences II, Room 165 Lat +36.99855 1156 High Street Voice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064 https://www.ucolick.org/~sla/ Hgt +250 m
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.
On Thu 2020-11-12T14:48:13-0800 Paul Eggert hath writ:
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.
That makes me want to find the navigational charts for the British Honduras harbors which were then in use. Whatever time was being reported by the ships should correspond to whatever longitude in on the charts. Whether or not charts were right, any other value would risk shipwreck. Even when longitudes were obviously wrong, changing to a different set of charts with a different longitude was done with great caution and much prior warning. Further, for Belize the charts were secondary because navigation required visual confirmation, so they may have preserved wrong values of longitude longer than other harbors. -- Steve Allen <sla@ucolick.org> WGS-84 (GPS) UCO/Lick Observatory--ISB 260 Natural Sciences II, Room 165 Lat +36.99855 1156 High Street Voice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064 https://www.ucolick.org/~sla/ Hgt +250 m
On Thu 2020-11-12 14:48 -0800, Paul Eggert wrote:
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.
That article appears to have been widely quoted, without any byline or credit; free view of issue: https://news.hrvh.org/veridian/cgi-bin/imageserver.pl?oid=rocklandctyjournal... article: https://news.hrvh.org/veridian/?a=d&d=rocklandctyjournal19000825.2.65& "Rockland County Journal, 25 August 1900 STANDARDS OF TIME. ——————— THE DAY BEGINS AT SUNSET IN MO- HAMMEDAN COUNTRIES. ——————— Any Sort of Time Is Kept In China, While In Africa They Keep Very Good Time — Some Countries Use Two Standards of Time. ... At Belize, British Honduras, the clock over the courthouse, which furnishes the time for the town, is usually regulated by the time kept by the ships in the harbor. ..." Old Belize around the bay to the west, the Port Authority and Coast Guard further north, what appears to be the old Port of Belize, the Custom House, the Esso terminal, and the Pier, probably delineate the historical harbour: https://www.google.ca/maps/place/Port+of+Belize/@17.4790533,-88.2016211,1479... The Pier is probably the closest larger commercial vessels may now approach for fueling and unloading. The cays offshore are areas sailors would avoid. There is a winding harbour approach road from the east, starting south of Sandbore, generally south of Water Cay, through the reefs and cays due south of Belize City: http://fishing-app.gpsnauticalcharts.com/i-boating-fishing-web-app/fishing-m... This looks like one harbour and port where ships would wait offshore until the pilot boat came out to guide you safely in through the winding channels to a berth with enough draught to keep you afloat at low tide. There is a space on the chart labelled Sugar Berth A, which could have been a primary reference point for navigation historically. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised. [Data in binary units and prefixes, physical quantities in SI.]
On 2020-11-08 03:37, Paul Eggert wrote:
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.
Not true. Paragraph 2 of the ordinance says: "2. The Standard Time to be observed throughout the Colony for all purposes whatsoever, save as hereinafter provided, shall be the mean time of Longitude ninety degrees (90°) West, which is seven minutes, seventeen and twenty-seven hundredths seconds (7'17".27) later than the mean time at Belize and six hours later than the Greenwich mean time." Michael Deckers.
On 2020-11-07 01:18, Paul Eggert wrote:
On 11/6/20 1:59 PM, Michael H Deckers wrote:
-Zone America/Belize -5:52:48 - LMT 1912 Apr +Zone America/Belize -5:52:48 - LMT 1912 Apr 1
but the source is quite clear that it should be +Zone America/Belize -5:52:43 - LMT 1912 Apr 1
Unfortunately it's not so clear. Here's a citation to the source:
# Definition of Time Ordinance, 1927 (No.4 of 1927) [1927-04-01] # Ordinances of British Honduras Passed in the Year 1927, p 19-20 # https://books.google.com/books?id=LqEpAQAAMAAJ&pg=RA3-PA19
It says that standard time was established as -06 on 1912-04-01, and that -06 was 00:07:17.27 later than the local mean time at Belize. However, by my calculations -05:52:42.73 is longitude 88° 10′ 40.95″ W, which Google Maps says is in the ocean east of Belize city, so this was not LMT in Belize city.
To my mind what matters here is what was the legal time in Belize city before 1912-04-01. If there was no law or it was just LMT, no change needs to be made. If it was -05:52:42.73 then we need to find out when that legal time was instituted (perhaps for all of British Honduras?), and insert a transition from LMT to -05:52:42.73 at the appropriate date.
One constraint we like to follow is that the LMT longitude corresponds to the longitude in zone1970.tab.
You can't really make accurate judgments about anything based on Google Maps (notice they do not show any geographical grid or claim any geographical accuracy), except maybe within the Continental US, possibly because they use a WGS84 spherical Mercator projection, rather than the ellipsoid, which results in errors (except where that projection matches the ellipsoid), apparently higher at higher elevations, and they seem to use the NAD83 North American Datum in North America, but the datum used must vary elsewhere, and lacks documentation in some areas. Compare published geographic coordinates of current geodetic control points with where those coordinates appear on Google Maps and you will see the local errors and their magnitudes. I have friends who get numerous drive-bys of their acreage apparently due to "Google Maps" leading those who blindly follow such to believe their county road crosses a "near grade" railway line, despite online maps showing the nearest such roads 2-3 sections away, and the actual railway line elevation in the area varying from the terrain by a couple of metres either way. https://support.esri.com/en/technical-article/000009982 "Google Maps ... use a spherical-only Mercator projection based on the World Geodetic System (WGS) 1984 geographic coordinate system (datum). This Mercator projection supports spheres only, unlike [other] Mercator implementation, which supports ... ellipsoids. To emulate the sphere-only Mercator, it is necessary to use a sphere-based geographic coordinate system (GCS) to use the correct Mercator equations. This sphere-based geographic coordinate system is called 'WGS 1984 Major Auxiliary Sphere'." Historically and currently, other, possibly more local datums, were and are used for geographic coordinates, nowadays often based on WGS84 spheroid models, corrected by continuous GNSS observation cross-references, VLBI observations, and gravimetry at active control points, to some ITRF, and usually more accurate locally. Original (astronomically referenced) survey accuracies are often of the order of a metre, compared using modern methods, and modern corrections made, even at remote locations, tend to be on the order of only metres in 3D, mainly due to changes in reference frames, spheroid models, and datums (causing the largest variations). http://caribjes.com/CJESpdf/CJES%2037-1%20-%20Miller.pdf " Table 1. Parameters of Some Spheroids Spheroid Name Semi-major Semi-minor Flattening, f Eccentricity Axis, a (m) Axis, b (m) squared, e2 Clarke 1858 6378293.645 6356617.938 1/294.26 0.006785 Clarke 1866 6378206.400 6356583.800 1/294.9787 0.006769 Clarke 1880 6378249.145 6356514.870 1/293.465 0.006804 Clarke 1880 6378249.145 6356514.966 1/293.4663 0.006803 modified South American 6378160.000 6356774.719 1/298.25 0.006695 1969 International 6378388.000 6356911.946 1/297 0.006723 1924 ... Table 2. Projections Adopted Country Datum Spheroid Projection ... Belize NAD 1927 Clarke 1866 TM & UTM British Honduras 1922 Clarke 1858 TM Colony Coordinates ... Honduras NAD 1927 Clarke 1866 TM (with UTM grid) NAD 1927 Clarke 1866 Honduras Lambert N&S Fort Charles Flagstaff Clarke 1866 Jamaica Lambert Metre ..." http://www.asprs.org/a/resources/grids/03-2009-belize.pdf "The original datum established for Belize is the Sibun Gorge Datum of 1922 where the astronomical coordinates of the origin are: Φo = 17º03’40.471”S, Λo = –88º37’54.687”W, and the ellipsoid of reference is the Clarke 1858 where: a = 6,378,293.645 m, 1/f = 294.26. The Colony Coordinates used the datum origin for the Transverse Mercator projection with a scale factor at origin of unity, a False Northing = 445,474.83ft, a False Easting of 217,259.26ft, and the unit of measure is where 1 meter = 3.28086933 Jamaican feet. Another datum known to exist is called the Jesuit College Flagstaff, probably being the origin for a local hydrographic survey. With aerial photography flown in 1969 and 1972, a series of 1:50,000 scale topographic maps were produced by the British Directorate of Overseas Surveys (DOS). The coordinate reference system currently used in Belize is the North American Datum of 1927, presumably introduced in the 1950s by the U.S. Army Map Service’s Inter-American Geodetic Survey. ... The available 1:50,000 scale maps of Belize on the NAD27 are over-printed with the UTM Grid. According to TR 8350.2, the three-parameter datum shift for Central America including Belize From NAD27 To WGS84 is: ΔX = 0m±8m, ΔY = +125m±3m, ΔZ = +194m±5m, and is based on a 19-point solution in 1987." So with some GIS software and experimentation, current accurate values could be recalculated, but historically and navigationally, time and latitude were important, and as accurate as the technology of the day could make it. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised. [Data in binary units and prefixes, physical quantities in SI.]
participants (5)
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Brian Inglis -
Michael H Deckers -
P Chan -
Paul Eggert -
Steve Allen