Discussion:
Way OT: Daylight Savings Time and law enforcement
Add Reply
That Derek
2019-11-02 22:26:45 UTC
Reply
Permalink
At 2AM on Sunday 11/03/2019, most of the USA will set their clocks back one hour in keeping with established Daylight Savings Time strictures. This essentially creates two one-AM hours.

How do law enforcement entities reckon with this once-a-year anomaly? Say a car accident is documented to have occurred at 01:17 during the first one-AM hour, and then a DOA is clocked at the seconnd 01:17 -- how do the police blotters differentiate the two different 01:17's?

Would the first be 01:17 Daylight Time and the second Standard Time? Or, with "Eastern Time" serving as template, would it be 01:!7 EDT and 01:17 EST, respectively?

Answer me that, Mister Green Lantern!
A Friend
2019-11-03 02:10:54 UTC
Reply
Permalink
Post by That Derek
At 2AM on Sunday 11/03/2019, most of the USA will set their clocks back one
hour in keeping with established Daylight Savings Time strictures. This
essentially creates two one-AM hours.
How do law enforcement entities reckon with this once-a-year anomaly? Say a
car accident is documented to have occurred at 01:17 during the first one-AM
hour, and then a DOA is clocked at the seconnd 01:17 -- how do the police
blotters differentiate the two different 01:17's?
Would the first be 01:17 Daylight Time and the second Standard Time? Or, with
"Eastern Time" serving as template, would it be 01:!7 EDT and 01:17 EST,
respectively?
Answer me that, Mister Green Lantern!
First, I see what you did there.

Second, cops know to put EST and EDT in their logs for Sunday morning's
entries, and they generally don't limit this to 1 a.m.

Third, I look forward to the day when we get rid of this nonsense
altogether.
Kenny McCormack
2019-11-03 05:24:28 UTC
Reply
Permalink
Post by A Friend
Post by That Derek
At 2AM on Sunday 11/03/2019, most of the USA will set their clocks back one
hour in keeping with established Daylight Savings Time strictures. This
essentially creates two one-AM hours.
How do law enforcement entities reckon with this once-a-year anomaly? Say a
car accident is documented to have occurred at 01:17 during the first one-AM
hour, and then a DOA is clocked at the seconnd 01:17 -- how do the police
blotters differentiate the two different 01:17's?
Would the first be 01:17 Daylight Time and the second Standard Time? Or, with
"Eastern Time" serving as template, would it be 01:!7 EDT and 01:17 EST,
respectively?
Answer me that, Mister Green Lantern!
First, I see what you did there.
Second, cops know to put EST and EDT in their logs for Sunday morning's
entries, and they generally don't limit this to 1 a.m.
Yes, I'd be willing to agree that law enforcement has found a way to deal,
and that most other "critical path" social institutions have as well, but
there's a lot of "next tier" institutions that may not have, and it can
lead to confusion. The example that I often deal with is TV schedules
(specifically the type of displays that we are used to seeing on our
cable/satellite screens and/or on computer services, e.g., Sling). These
displays only have one slot available for a given day/time/channel, which
is fine for all but one particular hour of the year.
Post by A Friend
Third, I look forward to the day when we get rid of this nonsense
altogether.
Indeed. However, the trend seems to be toward making the nonsense
that is DST permanent, rather than to getting rid of it.

Note that certain states are working on making DST permanent, but so far
have not been able to implement it, due to quirks in federal regs.
--
No puppet.
No puppet.
You're a puppet.
RH Draney
2019-11-03 08:53:26 UTC
Reply
Permalink
Post by Kenny McCormack
Yes, I'd be willing to agree that law enforcement has found a way to deal,
and that most other "critical path" social institutions have as well, but
there's a lot of "next tier" institutions that may not have, and it can
lead to confusion. The example that I often deal with is TV schedules
(specifically the type of displays that we are used to seeing on our
cable/satellite screens and/or on computer services, e.g., Sling). These
displays only have one slot available for a given day/time/channel, which
is fine for all but one particular hour of the year.
I've already screwed up one recording this season because Arizona
doesn't futz with the clocks...since the UK went off Daylight Time last
week, a BBC program I record each weekend came on an hour later here and
I hadn't got round to changing the timer on the computer to
adjust...(fortunately, it's possible to replay the show I wanted later
so I got it recorded anyway)....

Next week, my DVR will skip recording the Rachel Maddow Show on one day
because there are too many overlapping shows whose local times *don't*
change with the seasons...since I've been listening to Rachel as an
on-demand podcast on the TuneIn app, this only affects my backup
arrangement....r
A Friend
2019-11-03 09:58:10 UTC
Reply
Permalink
Post by Kenny McCormack
Yes, I'd be willing to agree that law enforcement has found a way to deal,
and that most other "critical path" social institutions have as well, but
there's a lot of "next tier" institutions that may not have, and it can
lead to confusion. The example that I often deal with is TV schedules
(specifically the type of displays that we are used to seeing on our
cable/satellite screens and/or on computer services, e.g., Sling). These
displays only have one slot available for a given day/time/channel, which
is fine for all but one particular hour of the year.
I noticed early this morning that my Comcast program guide got around
the time change simply by listing the 1 a.m.-1:30 a.m. bloc twice in
succession. The grid was otherwise normal.
Adam H. Kerman
2019-11-03 15:57:23 UTC
Reply
Permalink
Post by A Friend
Post by Kenny McCormack
Yes, I'd be willing to agree that law enforcement has found a way to deal,
and that most other "critical path" social institutions have as well, but
there's a lot of "next tier" institutions that may not have, and it can
lead to confusion. The example that I often deal with is TV schedules
(specifically the type of displays that we are used to seeing on our
cable/satellite screens and/or on computer services, e.g., Sling). These
displays only have one slot available for a given day/time/channel, which
is fine for all but one particular hour of the year.
I noticed early this morning that my Comcast program guide got around
the time change simply by listing the 1 a.m.-1:30 a.m. bloc twice in
succession. The grid was otherwise normal.
You're both right. If the television schedule server uses UTC, then tv
schedules will use UTC with an offset from Greenwich for local time.
Then there's no conflict at 2 am on the day that Daylight Time becomes
effectives or ends.

If the television schedule still uses newspaper layout format, then
there's no concept of time zone nor Daylight Time.

This all goes back to decisions that were made in the architecture of
the earliest chipsets for personal computers, which nobody was ever
going to use in a real-time computer network. In the beginning, hookiing
up modems meant hideously expensive long-distance calls and files were
transferred from one computer to the next by a computer operator physically
transferring physical media.

In all chipsets for personal computers, the Hardware Clock -- Real Time
Clock -- CMOS Clock -- BIOS Time stored year, month, day, hour, minute,
and seconds. It was assumed that the localtime standard is used, that is,
dependent upon the geographical location of the computer. RTC is set by
the operating system, and required twice-a-year adjustment for the period
in which Daylight Saving Time is in effect. If the Hardware Clock was
used as the clock for any servers running on that machine, then clients
on the user's computer, if in another time zone, had to be aware of the
time offset between the two machines.

Only in chips manufactured since 2016 has firmware been able to store
timezone and use of Daylight time.

The System Clock -- the software clock -- exists in Unix and Linux systems
and modern MacOS's (which is based on Linux). It uses the Unix Epoch,
for which Time Zero is January 1, 1970, midnight at the start of the
calendar day in Greenwich. It doesn't have a concept of leap second and
thus isn't literally UTC, so that requires an adjustment at synchronization
with an Internet Time Server. The Linux kernel counts the number of timer
interrupts since bootup.

Note that the two clocks run independently of each other.

What is typically done at bootup: The operator sets the Hardware Clock
in BIOS to an approximate localtime. The System Clock is set from the
Hardware Clock with information about location, thus setting time zone
(offset from Greenwich) and use of Daylight time, and an Internet time
server is chosen. In 2016 and newer chipsets, this will set timezone and
use of Daylight time in the Hardware Clock as well. The System Clock can
be synchronized if the approximate time is within a few hours. There is
a calculation made in software as to the time it takes for the signal to
be sent from the server to the local machine. The Hardware Clock is then
set from the System Clock after each synchronization with the Internet
time server.

At synchronization with the Internet time server, the hardward clock
should be reset automatically from the System Clock.

Why do we have Standard Time at all? Railroads in the UK found it too
difficult to operate without the conductor keep time based on setting
his watch accurately to the station clock at each terminal, which was
set to London time. They standardized on Mean Time at the Royal
Observatory at Greenwich.

Communities along the way would typically use local solar time, setting
clocks at noon based on a sundial. But local apparent noon is at a
different time in each community based on longitude.

Why Greenwich? Ship navigation required being able to calculate
longitude, which required accurate time keeping. (Latitude was
calculated based on observation of the sky.) Because the UK was a
mercantile and naval world power, it had numerous navigation maps based
on Greenwich at Zero Longitude.

Standard Time came to the United States and Canada based on a series of
railroad conferences, culminating in a final railroad conference in
Chicago in 1883. There was some debate as to whether to standardize on
Greenwich or the Naval Observatory in Washington, but again, as there
were more navigation maps based on Greenwich as Zero Longitude, they
went with the British system of Standard Time.

It took decades for standard time to be used as local civil time
throughout the United States, though.

Because of Standard Time's railroad origins, Time Zones in the United
States were set by the Interstate Commerce Commission (today by the
Secretary of Transportation since the ICC sunset). States are assigned
to time zones. If there are states in two time zones, the time zone
boundary is set to county lines. When petitioned to change time zones,
the federal government considers whether local commerce is more heavily
associated in one direction or the other and petitions aren't always
approved.

UTC is set in the United States by a combination of the Navy on behalf
of the military and Commerce Department National Institute of Standards
and Technology for civilian purposes, but you know, it's coordinated
worldwide.

The period in which Daylight Saving Time is observed is set in federal
law, but states have the option of implementing it statewide or within a
time zone, thus we had the now-deprecated Indiana Time Zone in which
most of the state's counties were in Eastern Standard Time and did not
observe Daylight Time. This changed a number of years back. Because
Indiana is so far west in EST, during EDT, parts of the state are almost
on double daylight time. Counties in CST always observed Daylight Time.

Alaska and Hawaii remain on Standard Time throughout the year. Arizona
remains on Standard Time, except certain Indian reservations observe
Daylight Time.
A Friend
2019-11-03 19:49:15 UTC
Reply
Permalink
Post by Adam H. Kerman
Post by A Friend
Post by Kenny McCormack
Yes, I'd be willing to agree that law enforcement has found a way to deal,
and that most other "critical path" social institutions have as well, but
there's a lot of "next tier" institutions that may not have, and it can
lead to confusion. The example that I often deal with is TV schedules
(specifically the type of displays that we are used to seeing on our
cable/satellite screens and/or on computer services, e.g., Sling). These
displays only have one slot available for a given day/time/channel, which
is fine for all but one particular hour of the year.
I noticed early this morning that my Comcast program guide got around
the time change simply by listing the 1 a.m.-1:30 a.m. bloc twice in
succession. The grid was otherwise normal.
You're both right. If the television schedule server uses UTC, then tv
schedules will use UTC with an offset from Greenwich for local time.
Then there's no conflict at 2 am on the day that Daylight Time becomes
effectives or ends.
If the television schedule still uses newspaper layout format, then
there's no concept of time zone nor Daylight Time.
This all goes back to decisions that were made in the architecture of
the earliest chipsets for personal computers, which nobody was ever
going to use in a real-time computer network. In the beginning, hookiing
up modems meant hideously expensive long-distance calls and files were
transferred from one computer to the next by a computer operator physically
transferring physical media.
In all chipsets for personal computers, the Hardware Clock -- Real Time
Clock -- CMOS Clock -- BIOS Time stored year, month, day, hour, minute,
and seconds. It was assumed that the localtime standard is used, that is,
dependent upon the geographical location of the computer. RTC is set by
the operating system, and required twice-a-year adjustment for the period
in which Daylight Saving Time is in effect. If the Hardware Clock was
used as the clock for any servers running on that machine, then clients
on the user's computer, if in another time zone, had to be aware of the
time offset between the two machines.
Only in chips manufactured since 2016 has firmware been able to store
timezone and use of Daylight time.
The System Clock -- the software clock -- exists in Unix and Linux systems
and modern MacOS's (which is based on Linux). It uses the Unix Epoch,
for which Time Zero is January 1, 1970, midnight at the start of the
calendar day in Greenwich. It doesn't have a concept of leap second and
thus isn't literally UTC, so that requires an adjustment at synchronization
with an Internet Time Server. The Linux kernel counts the number of timer
interrupts since bootup.
Note that the two clocks run independently of each other.
What is typically done at bootup: The operator sets the Hardware Clock
in BIOS to an approximate localtime. The System Clock is set from the
Hardware Clock with information about location, thus setting time zone
(offset from Greenwich) and use of Daylight time, and an Internet time
server is chosen. In 2016 and newer chipsets, this will set timezone and
use of Daylight time in the Hardware Clock as well. The System Clock can
be synchronized if the approximate time is within a few hours. There is
a calculation made in software as to the time it takes for the signal to
be sent from the server to the local machine. The Hardware Clock is then
set from the System Clock after each synchronization with the Internet
time server.
At synchronization with the Internet time server, the hardward clock
should be reset automatically from the System Clock.
Why do we have Standard Time at all? Railroads in the UK found it too
difficult to operate without the conductor keep time based on setting
his watch accurately to the station clock at each terminal, which was
set to London time. They standardized on Mean Time at the Royal
Observatory at Greenwich.
Communities along the way would typically use local solar time, setting
clocks at noon based on a sundial. But local apparent noon is at a
different time in each community based on longitude.
Why Greenwich? Ship navigation required being able to calculate
longitude, which required accurate time keeping. (Latitude was
calculated based on observation of the sky.) Because the UK was a
mercantile and naval world power, it had numerous navigation maps based
on Greenwich at Zero Longitude.
Standard Time came to the United States and Canada based on a series of
railroad conferences, culminating in a final railroad conference in
Chicago in 1883. There was some debate as to whether to standardize on
Greenwich or the Naval Observatory in Washington, but again, as there
were more navigation maps based on Greenwich as Zero Longitude, they
went with the British system of Standard Time.
It took decades for standard time to be used as local civil time
throughout the United States, though.
Because of Standard Time's railroad origins, Time Zones in the United
States were set by the Interstate Commerce Commission (today by the
Secretary of Transportation since the ICC sunset). States are assigned
to time zones. If there are states in two time zones, the time zone
boundary is set to county lines. When petitioned to change time zones,
the federal government considers whether local commerce is more heavily
associated in one direction or the other and petitions aren't always
approved.
UTC is set in the United States by a combination of the Navy on behalf
of the military and Commerce Department National Institute of Standards
and Technology for civilian purposes, but you know, it's coordinated
worldwide.
The period in which Daylight Saving Time is observed is set in federal
law, but states have the option of implementing it statewide or within a
time zone, thus we had the now-deprecated Indiana Time Zone in which
most of the state's counties were in Eastern Standard Time and did not
observe Daylight Time. This changed a number of years back. Because
Indiana is so far west in EST, during EDT, parts of the state are almost
on double daylight time. Counties in CST always observed Daylight Time.
Alaska and Hawaii remain on Standard Time throughout the year. Arizona
remains on Standard Time, except certain Indian reservations observe
Daylight Time.
Thank you very much for all of that.
David Carson
2019-11-03 21:12:37 UTC
Reply
Permalink
Post by A Friend
Third, I look forward to the day when we get rid of this nonsense
altogether.
On the rare occasion that I meet someone in my state legislature, it's the
only issue I raise. They generally express agreement that something ought
to be done without creating any expectations that they are going to do
anything.
Kenny McCormack
2019-11-03 22:02:16 UTC
Reply
Permalink
Post by David Carson
Post by A Friend
Third, I look forward to the day when we get rid of this nonsense
altogether.
On the rare occasion that I meet someone in my state legislature, it's the
only issue I raise. They generally express agreement that something ought
to be done without creating any expectations that they are going to do
anything.
Yeah, I like that. If I were going to be a single issue voter, this could
very well be the one I'd hang my hat on.

But the fact is that nothing ever will be done, because of these two,
competing, facts:
1) People love DST. This is completely insane, of course, but they do.

2) If you have year around DST, winter sunrises are just too damn late
(in temperate regions). This primarily affects school children.
And, won't somebody PLEASE think of the children???

So, I think we're pretty much stuck with our current 8-4 split.

P.S. Somebody in this thread claimed that Alaska does not observe DST.
As far as I can tell, this is not true. See:

https://www.timeanddate.com/time/change/usa/anchorage

This is not the only URL I could assert; just the most convenient.
--
Men rarely (if ever) manage to dream up a God superior to themselves.
Most Gods have the manners and morals of a spoiled child.
Adam H. Kerman
2019-11-04 13:40:54 UTC
Reply
Permalink
Post by Kenny McCormack
P.S. Somebody in this thread claimed that Alaska does not observe DST.
https://www.timeanddate.com/time/change/usa/anchorage
This is not the only URL I could assert; just the most convenient.
My error. Actually, I made two. Most of Alaska is in Alaska Time Zone,
which is -9/-8 offset from Greenwich. A portion of the Aleutian Islands
is in Hawaii - Aleutian Time Zone, which is -10/-9, but Hawaii remains
on standard time throughout the year.
Kenny McCormack
2019-11-17 12:05:02 UTC
Reply
Permalink
Post by Adam H. Kerman
Post by Kenny McCormack
P.S. Somebody in this thread claimed that Alaska does not observe DST.
https://www.timeanddate.com/time/change/usa/anchorage
This is not the only URL I could assert; just the most convenient.
My error. Actually, I made two. Most of Alaska is in Alaska Time Zone,
which is -9/-8 offset from Greenwich. A portion of the Aleutian Islands
is in Hawaii - Aleutian Time Zone, which is -10/-9, but Hawaii remains
on standard time throughout the year.
BTW, both Texas and Florida are like that, too. Most of the state is in
one time zone, but there is a tiny sliver on the extreme west of the state
that is different.

P.S. We should dispense with time zones (and DST) entirely and just all use UTC.
--
When I was growing up we called them "retards", but that's not PC anymore.
Now, we just call them "Trump Voters".

The question is, of course, how much longer it will be until that term is also un-PC.
A Friend
2019-11-04 03:19:02 UTC
Reply
Permalink
Post by David Carson
Post by A Friend
Third, I look forward to the day when we get rid of this nonsense
altogether.
On the rare occasion that I meet someone in my state legislature, it's the
only issue I raise. They generally express agreement that something ought
to be done without creating any expectations that they are going to do
anything.
I have noticed more discussion about doing something, but the
"something" is to impose DST year-round, so high noon will always fall
at 1 p.m. The political will to keep DST appears to flow from
contributions to politicians from the entertainment and amusement
industry, which thinks DST is good for business.

I say get rid of it, period. I'm tired of the absurdity and
inconvenience of it.
Adam H. Kerman
2019-11-04 13:57:16 UTC
Reply
Permalink
Post by A Friend
I have noticed more discussion about doing something, but the
"something" is to impose DST year-round, so high noon will always fall
at 1 p.m. The political will to keep DST appears to flow from
contributions to politicians from the entertainment and amusement
industry, which thinks DST is good for business.
Chicago is about 10 minutes east of the time zone center, so local mean
noon is -5:50/-4:50

I could do without the time change, but it's worth noting that if you're
east of the point of offset (whatever the term is for the meridan
divisible by 15 degrees), then the period in which Daylight Time does
not impose the same extreme anamoly as it does for those who live west.
Time zone boundaries tend to be extended to westward extremes anyway,
like Detroit and nearly the entire state of Michigan except for four
counties in the Upper Peninsula. That puts the Eastern Time Zone portion
of western UP on double daylight time in the summer as it's about 90
degrees west.
Post by A Friend
I say get rid of it, period. I'm tired of the absurdity and
inconvenience of it.
But do you live west or east of the meridian divisible by 15 degrees?
Kenny McCormack
2019-11-04 14:56:09 UTC
Reply
Permalink
In article <qppans$e2a$***@dont-email.me>, Adam H. Kerman <***@chinet.com> wrote:
...
Post by Adam H. Kerman
Time zone boundaries tend to be extended to westward extremes anyway,
like Detroit and nearly the entire state of Michigan except for four
counties in the Upper Peninsula.
Indeed. Until fairly recently, Detroit was in the Central Time Zone, as it
rightfully is. Political pressure is always in the eastward direction.

One effect of this is on the Lake Michigan beaches (west edge of the
state), summer sunsets (right around the Summer Solstice) are very late
(after 10 PM). This is very nice, but I'd imagine that the sunrises are,
as a result, pretty late as well.
--
No puppet.
No puppet.
You're a puppet.
A Friend
2019-11-04 19:50:55 UTC
Reply
Permalink
Post by Adam H. Kerman
Post by A Friend
I have noticed more discussion about doing something, but the
"something" is to impose DST year-round, so high noon will always fall
at 1 p.m. The political will to keep DST appears to flow from
contributions to politicians from the entertainment and amusement
industry, which thinks DST is good for business.
Chicago is about 10 minutes east of the time zone center, so local mean
noon is -5:50/-4:50
I could do without the time change, but it's worth noting that if you're
east of the point of offset (whatever the term is for the meridan
divisible by 15 degrees), then the period in which Daylight Time does
not impose the same extreme anamoly as it does for those who live west.
Time zone boundaries tend to be extended to westward extremes anyway,
like Detroit and nearly the entire state of Michigan except for four
counties in the Upper Peninsula. That puts the Eastern Time Zone portion
of western UP on double daylight time in the summer as it's about 90
degrees west.
Post by A Friend
I say get rid of it, period. I'm tired of the absurdity and
inconvenience of it.
But do you live west or east of the meridian divisible by 15 degrees?
I live at 77 degrees W, so, a little bit west.
That Derek
2019-11-04 03:49:45 UTC
Reply
Permalink
Since the fall-back time change day now occurs on the first Sunday o November, the same day as the running of the NYC Marathon, why can't the time-change occur while the race is going on so that somebody can win it in one-hour-and-change rather than two-hours-and-change?
Kara
2019-11-04 06:22:08 UTC
Reply
Permalink
Post by That Derek
At 2AM on Sunday 11/03/2019, most of the USA will set their clocks back one hour in keeping with established Daylight Savings Time strictures. This essentially creates two one-AM hours.
How do law enforcement entities reckon with this once-a-year anomaly? Say a car accident is documented to have occurred at 01:17 during the first one-AM hour, and then a DOA is clocked at the seconnd 01:17 -- how do the police blotters differentiate the two different 01:17's?
Would the first be 01:17 Daylight Time and the second Standard Time? Or, with "Eastern Time" serving as template, would it be 01:!7 EDT and 01:17 EST, respectively?
Answer me that, Mister Green Lantern!
Or what about bars? They might close at 2am, and when last call was at 1:45am, well it's best to either not be all that sober, or to just stay home that night.
J.D. Baldwin
2019-11-05 18:18:02 UTC
Reply
Permalink
Incidentally, if you're the watchstander from 0000-0400 when the
ship is headed west, you're just screwed. Your midwatch is going
to be five hours long.
Ok, JD, now tell us what happened when your ship passed
the International Date Line...
We had an expression in the Navy: "They can't take away your
birthday." (You can see what's coming here.) It meant, roughly,
"Well, the consequences of this might be bad, but whatever the
worst-case scenario is, they at least can't do that."

We did in fact have one of the guys in my division (air-traffic
control) lose his birthday in a transit across the International Date
Line. So, yeah, they absolutely *can* take away your birthday.
--
_+_ From the catapult of |If anyone objects to any statement I make, I am
_|70|___:)=}- J.D. Baldwin |quite prepared not only to retract it, but also
\ / ***@panix.com|to deny under oath that I ever made it.-T. Lehrer
***~~~~----------------------------------------------------------------------
Loading...