Hold Your Horses, Orion — The DST Police Are Here

The constellation Orion (right) followed by Sirius (far left) tilts off to the west around 10:30 p.m. standard time. Starting tomorrow we’ll see the same scene at 11:30 p.m., one hour later. Bob King

I was surprised several nights ago when I saw that Orion already tipping over in the west by 10:30 p.m. Is winter really on its way out? With a snowstorm in today’s forecast, I doubt it, but daylight saving time (DST) begins tomorrow, so spring must be close, right? As we set your clocks forward an hour tonight, we artificially shift the balance of day and night, taking an hour from the morning and adding it on to the evening. Tonight the sun sets around 6 p.m. for many localities; tomorrow night it lingers until 7.  Likewise, this morning’s 6:30 a.m. sunrise becomes Sunday’s 7:30 a.m. sunrise.

The time shift also affects the positions of the stars as read by your clock. We can check those positions using the meridian as a reference. The meridian a great circle in the sky that begins at the due south point of the southern horizon, passes directly overhead and continues to the due north point of the northern horizon. It circles back under the Earth and meets itself again at the southern horizon. When a star crosses the meridian, it reaches its highest point in the sky.

Tonight at 8 p.m. standard time, Orion stands more than a fist west of the meridian in a dark sky. Sunday night it’s much closer at the same time, though it will still be twilight at 8 p.m. Stellarium

Tonight at 8 p.m. standard time, Orion stands more than a fist to the right (west) of the meridian in a dark sky, but tomorrow night at 8 p.m., it’s only a couple degrees west of the meridian. The change to daylight time “pulls back” the constellations, in effect delaying Orion’s setting by an hour. And not just Orion but every constellation west of the meridian. Likewise, daylight time delays the rising of every constellation in the eastern sky by an hour. putting the reigns on Orion. Arcturus will be up at 9 tonight, but we’ll have to wait till 10 to see it Sunday night.

Blue areas observe daylight time; red areas never have, and orange areas once did but have since abolished it. Wikipedia

In the end, by setting our clocks forward, we actually artificially stall the progress of the seasonal stars an hour. A lot of people I know love the return of daylight time for its extra hour of evening light, forcing spring as it were. But the fuss of bouncing back and forth between daylight and standard time rattles others. Last year, California legislators to put the issue to the voters last year. The people spoke and chose to keep daylight time the entire year. Now, the legislature has to agree with a two-thirds majority to approve it or not. Even if it is approved, nothing will happen because the Uniform Time Act of 1966 stipulates that states that observe DST must “begin and end on federally mandated dates.” Because California would still observe daylight time (permanently), it would be in conflict with federal law’s mandated dates.

They could have opted out like Arizona and Hawaii did but chose not to because of pressure from youth sports leagues that would lose daylight for evening games and practice. What beast have we unleashed on the world?

8 Responses

  1. kevan hubbard

    Bob,your map misses Australia and New zealand.if I recall the temprate,in climate not drink!, Australian states have it but the tropical ones don’t.im going to guess New Zealand uses DST.more tropical places don’t use it as day length does change much down there.although I don’t know why sports teams would be concerned about dst as they love floodlit skies above their fields despite the number of daylight hours to run around with balls!

      1. kevan hubbard

        Must be my device, it’s cut off on my phone roughly on a line up and down from the Bangladesh burma border.

        1. astrobob

          Hmmm … I wonder what’s up. I just double-checked and see the whole thing on main computer and laptop. If you turn your phone sideways, does it help?

          1. kevan hubbard

            No my world remains smaller!got it wrong border wise cut off roughly level with Iran/Pakistan border.

  2. Brian Rajala

    Australia, New Zealand on my Smartphone screen.

    If people want year around DST, get up an hour early, start work an hour early? Problem solved.
    I sometimes question the early March start.

    1. kevan hubbard

      When I did Bob’s email on my tablet I got the full map but via the smart phone sort of cut off around the Iran Pakistan border a bit over into Pakistan.strange Japan doesn’t do DST being a template nation. I have no firm views either way on the matter.these days most clocks change the time themselves but in the days of wind up clocks and watches it was a nuisance!we use to have a fellow that always came to work 1 hour late,funnily enough he never came in early when the clocks went the other way!

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