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[vdeane]

The time zones in this country are skewed quite a bit west of where they should be based on longitude.

This assessment of "should be" presumes that the idealized time zone placement involves keeping clock time as close to solar time as feasible while still only working in 1-hour increments.

I would counterargue that there is a reason why time zones are "skewed west", and point out that this phenomenon is not unique to the US, it repeats itself globally. Note how on this map there is a lot more red (places ahead of solar time) than blue (places behind solar time). This suggests that there is perhaps a natural preference for being ahead of solar time, and this is consistent with the reason we have DST: people like later sunsets and dislike earlier sunrises.

Indeed, I have found personally that when I travel, places which are towards the western edge of time zones are more pleasant to be in than places that are towards the eastern edge of time zones - because when operating on a normal schedule the places towards the western edge afford me more daylight to work with.

Ergo, I am going to argue instead that our time zones are not skewed far west enough. I concocted this myself a few months ago:

This includes time zones ranging from GMT-4 (pink) to GMT-11 (red)

This map presents an "always round up" scenario. Except for some small pockets near the eastern edges, solar noon will fall between 12:00 and 13:00 local time when DST is not in effect. (Almost) everyone gets to live ahead of solar time instead of behind it.

Note that this was a quickly thrown together thing so it could stand some potential tweaking in order to better align some areas with the nearest large city. But it's meant to demonstrate the general idea, not to be perfect.

If we did that, I would hope DST would be abolished, because if not, it would lead to some absurdly late sunrises.  Although, globalizing that idea, maybe it would be a good idea to move the Prime Meridian to Casablanca, adjusting the offset boundaries accordingly so that more places could be in the "correct" time zone?

[tradephoric]

Tell me why there was overwhelming bipartisan support for the repeal of permanent DST back in the 70s.  What drove it to be repealed?

Basically all of the reasons that everyone hates DST in November multiplied by 80.
1) Kids going to school in the dark (and many more waiting for buses or walking to the bus stop in the dark)

A lot of research has been done involving the circadian rhythm of school aged children that wasn’t known back in the 70s.  Today, the American Academy of Pediatrics recommends that middle and high schools start at 8:30 a.m. or later to give students the opportunity to get the amount of sleep they need, but most American adolescents start school too early.  In fact, according to the National Center for Education Statistics data from 2015-16, only 14.4% of high schools start the school day at 8:30 a.m. or later.  I would argue that a change to permanent DST in this country should be accompanied by hour later school start times throughout the country.  That way the lighting conditions of kids going to school would be the same as the pre-DST conditions while at the same time leading to school start times that more closely match AAP recommendations.

2) Traffic accidents in the morning

You aren’t looking at the whole equation if you are only considering morning fatalities.  A 2004 study analyzed the effects of daylight saving time on US pedestrian and motor vehicle occupant fatalities and estimated that permanent DST would reduce pedestrian fatalities by 171 per year and reduce motor vehicle occupant fatalities by 195 per year. 

The effects of daylight and daylight saving time on US pedestrian fatalities and motor vehicle occupant fatalities
https://www.sciencedirect.com/science/article/abs/pii/S0001457503000150

3) Energy savings (the purpose for which it was enacted) didn't materialize and the big concern about it (because of the Arab Oil Embargo) disappeared.

After Bush extended DST in 2005, the Department of Energy studied the impacts of extended Daylight Saving Time on national energy consumption.  The Energy Policy Act of 2005 extended the duration of Daylight Saving Time in the spring by changing its start date from the first Sunday in April to the second Sunday in March, and in the fall by changing its end date from the last Sunday in October to the first Sunday in November.  A report was released to Congress in October 2008 that concluded “the total electricity savings of Extended Daylight Saving Time were about 1.3 Tera Watt-hour (TWh). This corresponds to 0.5 per cent per each day of Extended Daylight Saving Time.” 

Impact of Extended Daylight Saving Time on National Energy Consumption
https://www.energy.gov/sites/prod/files/2015/05/f22/epact_sec_110_edst_report_to_congress_2008.pdf

And even if DST doesn’t reduce energy consumption during the hot summer months, not many people are complaining because people enjoy more sunshine during their summer evenings.  This is mainly conceptual, but below is a rough idea of the potential energy savings Daylight Saving Time provides by month (ie. negative energy savings during the hot summer months but positive savings during the cold winter months compared to standard time).  If there is a 0.5% energy savings when DST was extended into November back in 2005, what energy savings might we see if it was extended year-round? 

[vdeane]

I don't see how DST would save any energy at all in the winter.  Yes, you'd have natural light for another evening hour, but you'd also lose natural light for a morning hour.  Most people do not wait until 8:30 AM to roll out of bed because we work for a living, and that's in the eastern half of a time zone - in the western half, sunrise wouldn't be until 9:30!

Re: school children, the easiest way to get later start times for middle/high school is to swap them with primary/elementary school, so somebody would still be stuck waiting for the bus or walking in the dark.  Not to mention that shifting the clocks forwards would cancel out any gains from moving the school start time in the first place, bringing us right back to where we are now.  Circadian rhythms, after all, are based on the sun, not clocks.

[michravera]

Tell me why there was overwhelming bipartisan support for the repeal of permanent DST back in the 70s.  What drove it to be repealed?

Basically all of the reasons that everyone hates DST in November multiplied by 80.
1) Kids going to school in the dark (and many more waiting for buses or walking to the bus stop in the dark)

A lot of research has been done involving the circadian rhythm of school aged children that wasn’t known back in the 70s.  Today, the American Academy of Pediatrics recommends that middle and high schools start at 8:30 a.m. or later to give students the opportunity to get the amount of sleep they need, but most American adolescents start school too early.  In fact, according to the National Center for Education Statistics data from 2015-16, only 14.4% of high schools start the school day at 8:30 a.m. or later.  I would argue that a change to permanent DST in this country should be accompanied by hour later school start times throughout the country.  That way the lighting conditions of kids going to school would be the same as the pre-DST conditions while at the same time leading to school start times that more closely match AAP recommendations.

2) Traffic accidents in the morning

You aren’t looking at the whole equation if you are only considering morning fatalities.  A 2004 study analyzed the effects of daylight saving time on US pedestrian and motor vehicle occupant fatalities and estimated that permanent DST would reduce pedestrian fatalities by 171 per year and reduce motor vehicle occupant fatalities by 195 per year. 

The effects of daylight and daylight saving time on US pedestrian fatalities and motor vehicle occupant fatalities
https://www.sciencedirect.com/science/article/abs/pii/S0001457503000150

3) Energy savings (the purpose for which it was enacted) didn't materialize and the big concern about it (because of the Arab Oil Embargo) disappeared.

After Bush extended DST in 2005, the Department of Energy studied the impacts of extended Daylight Saving Time on national energy consumption.  The Energy Policy Act of 2005 extended the duration of Daylight Saving Time in the spring by changing its start date from the first Sunday in April to the second Sunday in March, and in the fall by changing its end date from the last Sunday in October to the first Sunday in November.  A report was released to Congress in October 2008 that concluded “the total electricity savings of Extended Daylight Saving Time were about 1.3 Tera Watt-hour (TWh). This corresponds to 0.5 per cent per each day of Extended Daylight Saving Time.” 

Impact of Extended Daylight Saving Time on National Energy Consumption
https://www.energy.gov/sites/prod/files/2015/05/f22/epact_sec_110_edst_report_to_congress_2008.pdf

And even if DST doesn’t reduce energy consumption during the hot summer months, not many people are complaining because people enjoy more sunshine during their summer evenings.  This is mainly conceptual, but below is a rough idea of the potential energy savings Daylight Saving Time provides by month (ie. negative energy savings during the hot summer months but positive savings during the cold winter months compared to standard time).  If there is a 0.5% energy savings when DST was extended into November back in 2005, what energy savings might we see if it was extended year-round? 

Conceptual? Is that another name for "I strongly believe it because I want it to be so, but have no evidence for it"?
Look. I was there. It was a bad idea then. It would be a worse idea now (if only because we know better and don't have to repeat the mistake).

All that I have to say is "How many people sign up to work 4AM to Noon?" The answer is "not enough to fill the jobs that require them without incentive pay!" CASE CLOSED!

[GaryV]

 If there is a 0.5% energy savings when DST was extended into November back in 2005, what energy savings might we see if it was extended year-round? 

We tried that once.  (See Nixon, Oil Embargo.)  It didn't work - more energy was used in the winter DST.  Part of the problem is that when it gets light so late in the morning, you turn on the lights so you can see.  And forget to turn them off.

There was a political cartoon in the era.  Nixon was speaking:  "This is how you make a blanket warmer.  First you cut one foot off this end.  Then you sew it onto the other end.  It's called Daylight Saving Time."

[tradephoric]

I don't see how DST would save any energy at all in the winter.  Yes, you'd have natural light for another evening hour, but you'd also lose natural light for a morning hour.  Most people do not wait until 8:30 AM to roll out of bed because we work for a living, and that's in the eastern half of a time zone...

If we really wanted to reduce energy consumption in this country, we would run standard time during the summer and DST during the winter.  We got it backwards.  In the winter when people are trying to heat their homes, maximizing the waking hours of daylight helps reduce energy consumption (the sun is a natural heating source).  OTOH, in the summer when people are trying to cool their homes, the sun being out doesn’t help that effort and minimizing the waking hours of daylight would help reduce energy consumption.  The 2005 Energy Department study even touches on AC usage as a reason why some southern portions of the United States exhibited slightly smaller impacts of Extended Daylight Saving Time on energy savings when compared to northern regions...

During Extended Daylight Saving Time, electricity savings generally occurred over a three- to five-hour period in the evening with small increases in usage during the early-morning hours. On a daily percentage basis, electricity savings were slightly greater during the March (spring) extension of Extended Daylight Saving Time than the November (fall) extension. On a regional basis, some southern portions of the United States exhibited slightly smaller impacts of Extended Daylight Saving Time on energy savings compared to the northern regions, a result possibly due to a small, offsetting increase in household air conditioning usage.

in the western half, sunrise wouldn't be until 9:30!

You are assuming that the 48 states that currently observe DST would continue to observe DST if the nation went to permanent DST.  It's important to realize as part of the Uniform Time Act of 1966 that States can opt out of DST.

[tradephoric]

Look. I was there. It was a bad idea then. It would be a worse idea now (if only because we know better and don't have to repeat the mistake).

We tried that once.  (See Nixon, Oil Embargo.)  It didn't work - more energy was used in the winter DST.  Part of the problem is that when it gets light so late in the morning, you turn on the lights so you can see.  And forget to turn them off.

Ok guys, but where is the study that shows permanent DST was a failure at reducing energy costs back in the winter of 1974?

All that I have to say is "How many people sign up to work 4AM to Noon?" The answer is "not enough to fill the jobs that require them without incentive pay!" CASE CLOSED!

For someone who wants to enjoy more evening daylight after they get home from work during the winter, working 4AM to Noon is an option.  It's just not a practical option for most people.. but that doesn't mean they wouldn't enjoy the extra sunlight.

[tradephoric]

1975:  The Daylight Saving Time Study (DOT)

Significant results related to DST were found in four areas:  national electricity use was reduced by about 1%; national motor vehicle fatalities were reduced by about 0.7%; national school-age children fatal accidents were not significantly affected; and violent crime was reduced by 10 to 13% in Washington, D.C.

http://a.abcnews.com/images/2020/DOT%20DST%20study.PDF

[kphoger]

Let's get back to time zones.

[tolbs17]

What do you think about making Columbus Central?

30 minute timezones would come in handy. Especially for Maine. If anything, move Maine 30 minutes forward. not an hour.

[tradephoric]

OK, it's just hard to separate time zones from DST.  If this map assumes we stay on the current DST system, i really hate this map.  It would put Detroit in Central time meaning the sun would set at 4:02PM during the winter solstice.  I thought 5:02PM sunsets was bad enough in the winter but 4:02PM sounds horrible.

[jakeroot]

Let's get back to time zones.

In states where permanent DST is being considered, adjusting their standard time is an alternative option. The two concepts are related, and we are not off-topic.

[kphoger]

I'm fine with someone making a map that incorporates current DST times, no DST, or permanent DST (the latter two being functionally the same), but not debating the merits of one system or the other.  That's been hashed to death.

It seems to me that DST benefits northern areas more than it benefits southern areas, so maybe aiming for perpendicular-ish time zone boundaries isn't what's needed.  Maybe they should follow more of a diagonal.

[jakeroot]

It seems to me that DST benefits northern areas more than it benefits southern areas, so maybe aiming for perpendicular-ish time zone boundaries isn't what's needed.  Maybe they should follow more of a diagonal.

Interesting idea. The only Google reference I can find to "diagonal time zones" is this article from the Legislative Assembly of Manitoba, dated 1963. Go to page 1953, where MLA Gildas Molgat proposes a new way of looking at time zones; much of the PDF is about the discussion of extending DST.

We had originally introduced the motion in the House recommending what we felt was a reasonable compromise on this matter, and I appreciate that it is a question of compromise because you're not going to please everyone whichever way you go at it. It seems to me really that what is required in the long run is a new look at our time zones. I think the time zones were set up many years ago in different circumstances, and also that they do not necessarily apply the further north you go, because the facts are that in the southern regions, let's say in the southern part of the United States, in mid -summer the days are not as long as our own days are, and while a time zone may be applicable there to extend the time zones, as we do on a straight north-south line, means that in effect they are not in keeping with what the sun actually is doing and that they have a different effect at the southern fringe of the time zone than they have at the northern fringe of that time zone. It seems to me what is really required to settle this is to have our time zones actually on a slanted basis, and that this would permit then for a proper relationship. Now this sounds odd, I appreciate, but it is in fact what the sun does. My honourable friend from Thompson can certainly vouch for that because in mid -summer he has an extremely long day up there by comparison even to ourselves, so I would suggest that what is needed in the long run is a review of this right across the country and an analysis of whether we wouldn't be better off to change our time zones completely and have a new basis applicable more in keeping with what the sun is doing. I still prefer the compromise in this particular case that we had suggested originally.

Basically, you're not the first to think of this!

[renegade]

None of these solve anything.

[bandit957]

The real debate should be which major city each county should be assigned to, and which cities are considered major. I'm all for assigning each major city to the time zone where it would naturally be.

[Duke87]

https://i.imgur.com/Yudewrq.png

If your pink is Atlantic and your purple is Eastern, I can live with that.

Yes, purple is Eastern.

If we really wanted to reduce energy consumption in this country, we would run standard time during the summer and DST during the winter.  We got it backwards.  In the winter when people are trying to heat their homes, maximizing the waking hours of daylight helps reduce energy consumption (the sun is a natural heating source).  OTOH, in the summer when people are trying to cool their homes, the sun being out doesn’t help that effort and minimizing the waking hours of daylight would help reduce energy consumption.

Nnnn... so, first of all, it needs to be kept in mind that only 40% of energy used by buildings in the US is used by residential buildings. To get the full picture you can't just focus on what people are doing in their homes, you need to also focus on what businesses are doing.

As things stand, the daily temperature in the summer tends to peak around 5 PM (with DST), with it being fairly close to peak for a few hours before and a couple hours after. This peak occurs right around when a lot of people are leaving work.
In a scenario where standard time were used in the summer, this peak would be at 4 PM instead - and this would have the effect of creating a larger overlap between the hottest hours of the day and the hours of the day when offices (among some other commercial, industrial, or civic/institutional buildings - depending on their operating hours) are occupied.

Might this be counterbalanced by a smaller overlap between the hottest hours of the day and when residences are occupied? Maybe, but there would not be savings realized during this time period in residences where someone is home in the afternoon.


Something else to consider here is the impact that a clock shift has on the overlap between occupancy and when an onsite solar PV array is generating electricity. Currently, areas with a lot of solar production are already starting to see some of their peaks for utility electric demand shift later into the evening, with it starting to be driven by when solar production drops off rather than by when air conditioning usage peaks.
A shift to standard time in the summertime would exacerbate this by increasing the number of hours in the evening/night when people are awake and using electricity but solar PV systems are producing little to none of it.
This would then, in an a PV-dominated area, increase costs by increasing the required energy storage capacity. And this would generate a gross increase in energy consumption simply by virtue of the fact that energy storage is imperfect; over the course of charging and discharging batteries you lose some energy to heat, and you also then have to consume energy to keep the batteries cool.


I don't think it can reasonably be asserted with any level of confidence whether the impact on overall nationwide energy consumption of switching to standard time in the summer would be positive, negative, or a wash. There are too many different variables involved.
Even if we were to empirically try it, there are going to be confounding variables that cannot be fully controlled for.

[bandit957]

Is there a website where you can type in your location and it gives the actual natural time?

[GaryV]

Is there a website where you can type in your location and it gives the actual natural time?

Search for the naval observatory.

[tradephoric]

I don't see how DST would save any energy at all in the winter.  Yes, you'd have natural light for another evening hour, but you'd also lose natural light for a morning hour.  Most people do not wait until 8:30 AM to roll out of bed because we work for a living, and that's in the eastern half of a time zone - in the western half, sunrise wouldn't be until 9:30!

Read page 3 of this U.S. Department of Energy report if you want to see how relatively small increases in energy consumption during the morning was more than offset by large decreases in energy consumption during the evening when DST was extended (EDST). 

https://www.energy.gov/sites/prod/files/2015/05/f22/epact_sec_110_edst_report_to_congress_2008.pdf

Also few people living along the extreme western edge of a timezone would experience 9:30AM or later sunrises during the winter.  The only areas along the extreme western edge of a timezone that would experience sunrises at 9:30AM or later under permanent DST would be sparsely populated areas of the Upper Peninsula, North Dakota, and Montana.

[kalvado]

Is there a website where you can type in your location and it gives the actual natural time?

Not absolutely exact, but you may use https://www.timeanddate.com with your location.  Last column you will see  is "solar noon", you want it to be 12.00 for natural time.
Since solar noon drifts with time of year, you actually want it to be 11.43 today (largest deviation throughout the year). Any deviation between 11.43 and whatever you get in the last column is your offset from ideal

[GaryV]

The study cited a couple posts above was from when DST was extended into early March and to the first week of November.  It doesn't cover the winter.

[michravera]

OK, it's just hard to separate time zones from DST.  If this map assumes we stay on the current DST system, i really hate this map.  It would put Detroit in Central time meaning the sun would set at 4:02PM during the winter solstice.  I thought 5:02PM sunsets was bad enough in the winter but 4:02PM sounds horrible.

I would love to see a timezone map that showed zones with blending colors on adjacent time zones that showed the following basic criteria:

Sun never rises after 7:29 (or no nautical darkness after 6:45)
Sun never sets before 16:31 (or no nautical darkness before 17:15)
Sun is never overhead before 11:14
Sun is never overhead after 12:46

It may be hard farther north to avoid both rises after 7:29 (and nautical darkness after 6:45) and sets before 16:31 (or nautical darkeness before 17:15), but the map should show the section where that is impossible in a whitened color of the best fit while placing it on a time zone that avoids such failure for the longest portion of the year.
Areas that could be part of two time zones and meet all 4 basic criteria should be in a blended color (maybe something special, if they could be part of three).
There may be some boroughs in Alaska and counties in Canada's northern areas that are too large to keep on one time zone under my criteria. If so, do your best, but otherwise whole counties should stay on one zone. Media markets and urban affinity can be considered, but can not override the four basic criteria.

[webny99]

Let's get back to time zones.

Time zones and DST are inseparable, as we're finding out.
I wonder if this will be the first of many "DST in disguise" threads we'll have over the next few years.

Case in point:
Given approximately 9 hours of daylight during the winter, 7-8AM sunrise and 4-5PM sunset is optimal. Thus: the span of each time zone.Technically, properly aligning the time zones according to the above would not be related to DST, since we're on standard time in the winter. However, when we have DST lasting so late in the year that sunrises were later last week than they will be on the winter solstice, we have a major problem, and everything we just solved gets messed up come mid-October. Unacceptable.

Now, as a guide, the places that have an even 9 hours of winter daylight are roughly on/near the 43rd parallel.
(Edited to add: the above may have answered part of michravera's inquiry as to where it isn't possible to have pre-7:30 sunrise AND post-4:30 sunset. Not quite possible here, as we have 8:59 of daylight on the winter solstice! Interestingly, Syracuse has almost exactly your requirement (7:30 sunrise, 4:30 sunset). So, depending on your theory, Syracuse should either be the midpoint or the western boundary of EST. I'd prefer midpoint!)

So, there's the guidelines: now make the time zones. 

[1]

When we run into another dzlsabe-type thread, should we start talking about DST to force a lock?