Sunrise times across the US

Commenter anat linked to a very nice visual display of the latest sunrise times across the US if Daylight Savings Times becomes the fixed time all year long, as the legislation passed the US Senate decrees. The House of Representative has not agreed as yet.

When I lived in Cleveland, the latest sunrise was at about 8:00am Standard Time. One should bear in mind that it starts getting light about 30 minutes before the official sunrise. So while we had to get up in the dark to get ready, it would be light by the time I left for work and took the children to school.

If DST becomes permanent, Cleveland would end up in the western edge of the 8:30am-9:am band, which means it would be close to 9:00am, so that it would still be dark when I drop the children off at school and get to work at around 8:30am.

The people who live in the darker regions where sunrise is 9:00am or later will have to decide if they should change some things like school times so that children are not going to school in the dark. I suspect that if the change happens, many areas in the three darkest regions of the map will do as some commenters suggest, and that is change school times to nullify the effects of the change change.

I am not sure if work places will also follow suit, though it would be easier for them to make the change. They may be forced to under pressure to accommodate families with children who cannot leave for work before their children go off to school.


  1. flex says

    States like Michigan and Indiana could move to central time. IRRC, Michigan is on eastern time because the industry which developed around Detroit wanted to be in the same time zone as New York City. But with the increasing ambiguity of working hours, I don’t know if it really matters any more.

    It would take some getting used to. I remember when network television would announce sporting events as “9PM Eastern -- 6PM” Pacific, and since I live in Michigan I didn’t have to make any mental calculation to figure out what time it would be shown in my area. But a little bit of mental stimulation is good for you. And I no longer watch sports anyway.

  2. rblackadar says

    What struck me as odd, at first, was that the boundaries are not smooth curves. (I don’t mean the statutory time zone boundaries, of course, I mean the boundaries between the different color-coded regions, since the latter depend on physics, not convention.)

    But, the small print at lower left explains why: the map was calculated county by county. Seems like an odd way to display the info, but ok.

    There are sure some big counties in AZ, ID, CA, etc.

  3. rojmiller says

    Unfortunately there does not appear to be any perfect solution. Because time zones are approx. 1 hour wide, what works for Bangor Maine or Quebec City Quebec does not work for Marquette Michigan or Thunder Bay Ontario. Perhaps we have chosen to use DST in the summer as the best compromise?

    A good site to look up sunrise and sunset for any city, any time of the year is:
    Sunrise and Sunset Calculator — City Lookup

  4. Holms says

    In this arrangement, when are the latest / earliest sunsets? How close is 12PM to the sun’s zenith?

  5. Reginald Selkirk says

    Lying to ourselves is pathetic. Use Standard Time, and feel free to adjust the start of school and work according to season and latitude.

  6. Reginald Selkirk says

    @4: But, the small print at lower left explains why: the map was calculated county by county.

    That still leaves some room for uncertainty. Is it the earliest sunrise at any point in the county? The average sunrise for all points in the county? For the county seat? …

  7. says

    A month ago nobody was talking about moving to permanent DST. Suddenly, it’s a fait accompli. Why? And the reporting is completely lopsided. You hear that there is an increase in heart attack admissions following the spring change, but you don’t hear that the same study found a similar decrease in admissions after the fall change and concluded that there is no net annual effect. Same goes for the increase (and opposing decrease) in traffic accidents. It’s also reported that 2/3rds of the public doesn’t want to have to change the clocks, but it’s generally not reported that those same polls show that that 2/3rds is split in half, meaning that 1/3rd of the population wants year-round DST, 1/3rd wants year-round standard time, and 1/3rd wants to leave it the way it is. So why the sudden push to year-round DST? With all of the other problems we have, why does this get attention and immediate, bipartisan action?

  8. Trickster Goddess says

    @jimf: It’s not sudden. BC passed legislation to go on permanent DST 3 years ago, contingent on the switch by the west coast states which stated their intent to do so pending a change in federal law. They are only just now getting around to changing the law.

  9. DrVanNostrand says

    The fact that you don’t see that your argument applies exactly the same to people who prefer Standard Time is the only thing that’s pathetic.

  10. Trickster Goddess says

    I would like to see a similar map of earliest sunset times under standard time. Where I live, just north of Washington’s Olympic Pennisula, that would be between 4-4:30 pm.

    Just about every job I’ve ever had I had to leave for work in the dark in the winter under standard time. I even once had a job where I went to work in the dark, worked in a windowless building all day then went home in the dark, not seeing any daylight at all all week.

    These days I suffer from SAD and getting through the winter is a struggle. Having daylight until 5:30pm in the dead of winter would ameliorate that somewhat.

  11. VolcanoMan says

    I actually support permanent Daylight Saving Time (it’s a rare smart idea from a bunch of dumb politicians). I’m used to getting up and going out to catch a bus at 6:35 AM…by December, it’s not even twilight out when I walk into work. There is currently a period of 113 days where the sun rises after 7:45 AM (when I get to work); permanent Daylight Saving Time only adds TEN days to this, a really small difference (in my opinion). Moreover, I personally could not care less if the sun is rising at 9:20 AM in the middle of December or whatever; the difference between 8:20 AM and 9:20 AM is immaterial. However, the difference between a 4:30 PM and 5:30 PM SUNSET in mid-December is VERY significant, more than enough to make up for that 10 days of slightly darker mornings.

    So ultimately, I think it is early risers in northern states (and Canada, who will certainly go along with the change if the US implements it) who benefit most from this change, simply because they’re already being deprived of sun in the early morning in winter. Taking away an hour of sun in the morning, while they’re at work and not able to benefit from it, isn’t going to matter; GIVING them an hour of sun after their workday, when they CAN benefit from it is a great idea.

  12. Reginald Selkirk says

    @12: The fact that you don’t see that your argument applies exactly the same to people who prefer Standard Time is the only thing that’s pathetic.

    Except for the whole “lying to ourselves” part. Apparently you are very comfortable with self deception.

  13. Holms says

    #12 DrVanNostrand
    You seem to think the clock is totally arbitrary, as opposed to an attempt to map the progress of day and night.

  14. Deepak Shetty says

    All the folks in favor of schools shifting times aren’t working parents or what ?
    When it rains and /or it’s cloudy dark , how do children get dropped off that this it may be dark when it’s start of school becomes a problem ?

  15. Silentbob says

    @ 17 Reginald Selkirk

    Except for the whole “lying to ourselves” part. Apparently you are very comfortable with self deception.

    Hahahaha. I’m always amused by essentialism but this takes the cake. Apparently choosing to set our clocks differently to some other arbitrary convention is a “lie”. 🙂

    @ 18 Holms

    You seem to think the clock is totally arbitrary, as opposed to an attempt to map the progress of day and night.

    Well of course it’s not arbitrary Holms! Everyone knows that Chronos the god of time decreed that there are 24 hours in day! Instead of, say, 42. It’s written in the stars!

    Whereas, Daylight Savings -- that’s just totally arbitrary! It’s not like people were sick of knocking off after sunset after working in an office all day and never seeing daylight. It’s not as if “Daylight Savings” literally meant saving some of the day to enjoy after working hours. No, it was all completely arbitrary and come about for no reason whatsoever. Brilliant observation as usual Holms.


    Look, I’m fine people don’t like daylight savings. But for fuck’s sake be rational about it. Stop cherry-picking, “there’s less light in the morning”, while ignoring, “there’s more light in the evening”. And for fucks sake, stop writing as though the gods ordained one correct way of setting clocks, you sound like utter buffoons.

  16. beholder says

    Lying to ourselves is pathetic. Use sidereal time, and feel free to adjust the start of school and work according to our position in orbit around the sun.

  17. Holms says

    Following up on my #6, I found a solar calculator giving me those three exact things. Thanks, me!

    Use the map to pinpoint a location (the ‘US cities’ button up top will help with some references), hit the green “Create Sunrise/Sunset Tables For the Year” button and hey presto, a tab opens which gives three charts: the time of local sunrise, time of local sunset, and time of local noon, for every day of 2022 for that location. Here are the charts for Denver for starters. Notice the charts also give DST times clearly marked in green; the thing that will leap out at people is that DST gives a worse approximation to the course of the day than does Standard. Which is to be expected.

    To see what year-round DST will do to people’s lives, just add an hour to all times that aren’t green, and subtract an hour from all times that are green to see what would happen on year-round Standard. The existing inaccuracy becomes spectacular if constant DST is adopted, going from an offset of 15-46 minutes between 12PM and noon if Denver used year-round Standard, to 1hr 15m -- 1hr 46m with year-round DST.

    This approach is bonkers. People want to push the clocks around to make their lives more convenient, when they should be pushing the open and close times around instead whie keeping the count of time as true to the day cycle as possible. There will always be clunky areas that have an offset because the town/city/etc is near the edge of the time zone, there’s been no reason offered yet that makes the case for enlarging those errors. If school and etc. times are too early, the better approach is to push their open and close times back an hour. Many businesses will follow suit once government institutions implement such an approach.

    #20 silentbob
    I don’t recall any of our discussion touching on the number of subdivisions in a day, I could have sworn it was actually about aligning the clock with the physical cues of the day and night.

    You idiot.

  18. Reginald Selkirk says

    @20 @22: Specifically, a 24 hour clock with noon at the top is an analog of the motion of the sun across the sky. Silentbub should investigate the meaning of the ‘M’ in AM and PM.

  19. says

    Reginald @23. Yeah. Let me riff a bit about that M: meridiem. Meridiem means the middle of the day, that is when the sun passes the meridian of where one is located. The whole clock labeling system is set up based upon when the sun rises as high as possible during the day.

    The time zones already don’t really follow that: for them, the sun is (generally) highest at noon (standard time) on the eastern edge of the time zone, not in the middle as one would expect. Here near Columbus, Ohio, it occurs more or less around 12:35pm (modulo the analemma).

    And being the pedantic that I am, I really, really hate those who use 12:00pm for noon. 12:00 noon IS the meridiem, so noon should be 12:00m. Just “m”. (And, I pedantically assert that midnight should be 12:00im, inter-meridiem, between the days. Never convinced anybody, though. 🙂 )

  20. says

    @Deepak Shetty — Oh, yes, gods forbid parents have to… [gasp!] be responsible for their children! If you’re worried about your kid waiting in the dark, go wait with them, like a responsible parent should!

  21. billseymour says

    Mike the Mad Biologist has a post about how the bill got passed in the Senate.  TL/DR:  it was passed by unanimous consent, but most senators didn’t know it was happening, and several now say that they would have objected had they known.

    There are also quite a few messages being posted about this on the tz e-mail list.  It seems that lots of folks don’t understand the distinction of, on the one hand, making daylight saving time permanent, and on the other, making standard time permanent after adding one hour to the standard time offsets from UTC.  It makes a difference to computer programs that depend on the time of day; and it can take months for changes in civil time observance to filter down to all your devices.

    It’s also not clear how to say that parts of the country that don’t observe daylight saving time (currently Hawaii and that portion of Nevada that’s not part of the Navajo Nation) are allowed to keep doing what they’re doing.

    And how likely is it that Canada and Mexico will just follow the elephant in the room?  And if Mexico does, what about Central America?

    This was not well thought out at all.

  22. says

    Anyway, permanent DST didn’t last long the last time it was tried, and it’s been studied and isn’t really a good thing. Permanent Standard is objectively better.

  23. beholder says

    All y’alls time standards are arbitrary in the first place. Daylight and standard time both use mean solar time, which ultimately depends on observation of a (slightly) moving target being observed from a (slightly) jittery rotating frame with a significant velocity.

    I’m handing out free leap seconds to anyone who can point to a more objective time standard without having to look it up on Wikipedia.

  24. billseymour says

    beholder @29:  it’s GMT that’s based on astronomical observations.  Almost everywhere in the world, civil time is based on UTC which, in turn, is based on atomic clocks, although it does get a “leap second” added every once in a while to keep it within 0.9s of what the astronomy tells us.

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