Putting the Darkest Morning Behind Us

By: 
Aileen O’Donoghue, Priest Associate Professor of Physics

If you have been thinking it’s awfully dark in the morning, you are correct.  Due to the wisdom of the United States Congress, we won’t switch back to Standard Time until Sunday morning (11/3) at 2 a.m. seven weeks after the autumnal equinox!  We switched to Daylight Saving Time a mere 10 days before the spring equinox, the equivalent of switching to Standard Time on October 1.  If spring were symmetric with fall, we would have switched to Daylight Saving Time on February 6!  That would have been only 13 weeks on Standard time.

Staying on Daylight Saving Time this late into the fall makes sunrise very late.  In fact, the first two sunrises of November will be later than the latest sunrise of the winter!  Today, the sun will rose (over a flat horizon) in Canton at 7:38:40 am EDT.  On Saturday, it will rise at 7:40:01 a.m. EDT.  On Sunday it will rise at 6:41:23 a.m. EST.  Whew.  We’ll get another hour of light in the morning.  But, due to the motion and tilt of the Earth, we’ll gradually lose it so that on January 2, 2014, the sun will rise at 7:37:35 a.m. EST… almost three minutes EARLIER than this Saturday!  As you rise in the dark tomorrow, you can tell yourself that it is the darkest morning you’ll have until November 2014!

Meanwhile, of course, the evenings will get abruptly darker.  In fact, Senator Michael Enzi (R, WY) and Representative Fred Upton (R, MI) advocated that the “Energy Policy Act of 2005” in which the dates of Daylight Saving Time were set (second Sunday of March and first Sunday of November), should keep us on Daylight Saving Time long enough for the kids to be able to go trick-or-treating in more daylight.  On Halloween, therefore, the sun set at 5:50:40 p.m. EDT, whereas on Sunday, it will set at 4:46:35 p.m. EST.  So the kids were indeed out last evening when there was more light.

As winter approaches, we will continue to get darker in the evenings until Dec. 9 when the sun will set at 4:20:26 p.m. EST. Then the evenings will start getting lighter, albeit slowly.

Explaining why the earliest sunset and latest sunrise don’t occur on the solstice (Dec. 21 at 12:11 p.m.) is too complicated for this post, though I’m happy to explain it to anyone who is interested.  This Washington Post article may help, as may this one from Pikes Peak Photo.  There is excellent information about the Analemma, which causes this, on Sherm’s Homepage.  In particular, he shows images of the latest sunrise and earliest sunset, though they’re for Nova Scotia, not Canton, so our dates are different.

How exciting to know we’ll be past the darkest mornings for this winter by Sunday!