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Discussion of precise time and frequency measurement

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New stuff in my Tindie store

MS
Mark Sims
Tue, Dec 27, 2016 5:22 AM

Ahhh, the subtle wonders of time zones and DST changes...  Heather lets you set your time zone offset down to the second, and does not range limit the offset.  If you want UTC +987:65:43 it's yours!  There are a surprising number of places on with weirdo time zones.

I tried to find a manageable, self contained way to automatically calculate the time zone from lat/lon, but that's a losing battle.  Even getting it off the net is rather problematic.  I've thought about implementing a last-ditch emergency back-up plan of basing it on (longitude/15) but decided that was too un-time-nutty.

Heather has standard DST rules for USA, Europe, Australia, and New Zealand (assuming it hasn't yet gone the way of Atlantis).  But since DST rules can change with the stroke a a politician's pen, you can specify a custom rule.  The one current DST limitation is the time must change at an hour...  that would be easy enough to change.


The Pacific Ocean is large and very spread out.  So the Chatham Islands,

though part of New Zealand are 45 minutes ahead of New Zealand time.
That is a real nasty and unusual time change. Plus NZ daylight time
being GMT +13

Ahhh, the subtle wonders of time zones and DST changes... Heather lets you set your time zone offset down to the second, and does not range limit the offset. If you want UTC +987:65:43 it's yours! There are a surprising number of places on with weirdo time zones. I tried to find a manageable, self contained way to automatically calculate the time zone from lat/lon, but that's a losing battle. Even getting it off the net is rather problematic. I've thought about implementing a last-ditch emergency back-up plan of basing it on (longitude/15) but decided that was too un-time-nutty. Heather has standard DST rules for USA, Europe, Australia, and New Zealand (assuming it hasn't yet gone the way of Atlantis). But since DST rules can change with the stroke a a politician's pen, you can specify a custom rule. The one current DST limitation is the time must change at an hour... that would be easy enough to change. ---------------- > The Pacific Ocean is large and very spread out. So the Chatham Islands, though part of New Zealand are 45 minutes ahead of New Zealand time. That is a real nasty and unusual time change. Plus NZ daylight time being GMT +13
W
Wes
Tue, Dec 27, 2016 2:18 PM

Most of the citizens of the state of Arizona are smart enough to know that you
can't actually save any daylight with daylight savings time.  Hence, we remain
on Mountain Standard Time.

The Navajo Indian Nation, whose territory spans parts of three states, including
northeast AZ, decided to use DST.  However, the Hopi Nation, whose territory is
entirely within the Arizona portion of the Navajo Nation, stays on MST.

The polygamist Mormon town of Colorado City, Arizona and Hildale, Utah is
literally bisected by the state line.  Utah observes MDT so part of the town is
MDT and the other part is MST.  I reality, it's my understanding that the whole
town uses MDT.

(For such a tiny place, Colorado City has made a lot of news.  It was once known
as Short Creek.)

On 12/26/2016 10:22 PM, Mark Sims wrote:

Ahhh, the subtle wonders of time zones and DST changes...  Heather lets you set your time zone offset down to the second, and does not range limit the offset.  If you want UTC +987:65:43 it's yours!  There are a surprising number of places on with weirdo time zones.

I tried to find a manageable, self contained way to automatically calculate the time zone from lat/lon, but that's a losing battle.  Even getting it off the net is rather problematic.  I've thought about implementing a last-ditch emergency back-up plan of basing it on (longitude/15) but decided that was too un-time-nutty.

Heather has standard DST rules for USA, Europe, Australia, and New Zealand (assuming it hasn't yet gone the way of Atlantis).  But since DST rules can change with the stroke a a politician's pen, you can specify a custom rule.  The one current DST limitation is the time must change at an hour...  that would be easy enough to change.


Most of the citizens of the state of Arizona are smart enough to know that you can't actually save any daylight with daylight savings time. Hence, we remain on Mountain Standard Time. The Navajo Indian Nation, whose territory spans parts of three states, including northeast AZ, decided to use DST. However, the Hopi Nation, whose territory is entirely within the Arizona portion of the Navajo Nation, stays on MST. The polygamist Mormon town of Colorado City, Arizona and Hildale, Utah is literally bisected by the state line. Utah observes MDT so part of the town is MDT and the other part is MST. I reality, it's my understanding that the whole town uses MDT. (For such a tiny place, Colorado City has made a lot of news. It was once known as Short Creek.) On 12/26/2016 10:22 PM, Mark Sims wrote: > Ahhh, the subtle wonders of time zones and DST changes... Heather lets you set your time zone offset down to the second, and does not range limit the offset. If you want UTC +987:65:43 it's yours! There are a surprising number of places on with weirdo time zones. > > I tried to find a manageable, self contained way to automatically calculate the time zone from lat/lon, but that's a losing battle. Even getting it off the net is rather problematic. I've thought about implementing a last-ditch emergency back-up plan of basing it on (longitude/15) but decided that was too un-time-nutty. > > Heather has standard DST rules for USA, Europe, Australia, and New Zealand (assuming it hasn't yet gone the way of Atlantis). But since DST rules can change with the stroke a a politician's pen, you can specify a custom rule. The one current DST limitation is the time must change at an hour... that would be easy enough to change. > > ----------------
NS
Nick Sayer
Tue, Dec 27, 2016 3:51 PM

On Dec 26, 2016, at 9:22 PM, Mark Sims holrum@hotmail.com wrote:

Ahhh, the subtle wonders of time zones and DST changes...  Heather lets you set your time zone offset down to the second, and does not range limit the offset.  If you want UTC +987:65:43 it's yours!  There are a surprising number of places on with weirdo time zones.

It’s not so much that the code can’t do the right thing… it’s making the two-button, 7 digit UI not suck just to support oddball cases for people who aren’t actually purchasing the product. :)

I tried to find a manageable, self contained way to automatically calculate the time zone from lat/lon, but that's a losing battle.  Even getting it off the net is rather problematic.  I’ve thought about implementing a last-ditch emergency back-up plan of basing it on (longitude/15) but decided that was too un-time-nutty.

Yeah. Just the database of the connect-the-dot timezone lines for North America alone would probably blow the firmware budget for my hardware.

Heather has standard DST rules for USA, Europe, Australia, and New Zealand (assuming it hasn't yet gone the way of Atlantis).  But since DST rules can change with the stroke a a politician's pen, you can specify a custom rule.  The one current DST limitation is the time must change at an hour…  that would be easy enough to change.

I drew the line above NZ, but if more than a handful of people from there actually want to buy one, I’ll happily add it. Same goes for anywhere else. And the firmware is open and the board has an ISP header on it, so updating it yourself is also an option.


The Pacific Ocean is large and very spread out.  So the Chatham Islands,

though part of New Zealand are 45 minutes ahead of New Zealand time.
That is a real nasty and unusual time change. Plus NZ daylight time
being GMT +13


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> On Dec 26, 2016, at 9:22 PM, Mark Sims <holrum@hotmail.com> wrote: > > Ahhh, the subtle wonders of time zones and DST changes... Heather lets you set your time zone offset down to the second, and does not range limit the offset. If you want UTC +987:65:43 it's yours! There are a surprising number of places on with weirdo time zones. It’s not so much that the code can’t do the right thing… it’s making the two-button, 7 digit UI not *suck* just to support oddball cases for people who aren’t actually purchasing the product. :) > > I tried to find a manageable, self contained way to automatically calculate the time zone from lat/lon, but that's a losing battle. Even getting it off the net is rather problematic. I’ve thought about implementing a last-ditch emergency back-up plan of basing it on (longitude/15) but decided that was too un-time-nutty. Yeah. Just the database of the connect-the-dot timezone lines for North America alone would probably blow the firmware budget for my hardware. > > Heather has standard DST rules for USA, Europe, Australia, and New Zealand (assuming it hasn't yet gone the way of Atlantis). But since DST rules can change with the stroke a a politician's pen, you can specify a custom rule. The one current DST limitation is the time must change at an hour… that would be easy enough to change. I drew the line above NZ, but if more than a handful of people from there actually want to buy one, I’ll happily add it. Same goes for anywhere else. And the firmware is open and the board has an ISP header on it, so updating it yourself is also an option. > > ---------------- > >> The Pacific Ocean is large and very spread out. So the Chatham Islands, > though part of New Zealand are 45 minutes ahead of New Zealand time. > That is a real nasty and unusual time change. Plus NZ daylight time > being GMT +13 > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there.