21 December 2021
By the time the winter solstice arrives today at 10:59am we already will have gained three minutes at the end of the day.
Though the winter solstice has the shortest daylight — only 9 hours, 16 minutes and 57 seconds in Pittsburgh — it doesn’t have the earliest sunset nor the latest sunrise. That’s because the length of the solar day varies, solar noon to solar noon, while our clocks use the average day length of 24 hours. For a host of reasons, our clocks do not match solar time(*).
Thus the earliest sunset occurred 1 to 13 December in Pittsburgh and the latest sunrise won’t happen until 31 December and will linger for more than a week. See table below, built from information at timeanddate.com.
Pittsburgh PA Sunrise & Sunset near the Winter Solstice| Date | Sunrise | Sunset |
|---|---|---|
| 1 Dec 2021 (earliest sunset) to 13 Dec 2021 | 7:24 am to 7:34 am | 4:53 pm (earliest sunset) |
| 21 Dec 2021 (winter solstice) | 7:39 am ET | 4:56 pm ET |
| 31 Dec 2021 (latest sunrise) to 8 Jan 2022 | 7:43 am (latest sunrise) | 5:03 pm to 5:10 pm |
If you cue on sunrise the days will seem to get shorter into early January.
If you cue on sunset your day has already gained three minutes this month and is getting longer.
(*) For the ultimate in “Our clocks don’t match solar time” consider that Solar Noon happens around 1pm during Daylight Saving Time. Solar Noon is in the 12 o’clock hour, as it should be, during Standard Time.
(photo by Kate St. John)
Thank you for the chart. I am a sunset person, but now will note both. Happy Solstice. Liz
After we hit the solstice I have to remind myself that we are gaining daylight everyday even though it may not “feel” like it. Thanks for this.
My Hungarian grandmother used to say, after the solstice the day gets longer by one rooster step each day. I think it sounded more profound in Hungarian!
The mysterious Analemma!
https://en.wikipedia.org/wiki/Analemma
Analemma and the Equation of Time are in the pipeline for a future blog. Analemma also sounds like a good name for a baby girl. I wonder…
Only 89 days until spring! Looking forward to gaining more daylight. Wish I could say more sunlight, but we live in gray and cloudy Pittsburgh.