Martin Widlake's Yet Another Oracle Blog

And so the evenings start drawing out (honest!) December 13, 2011

I know I’ve blogged about this before, but it was early on when very few people read my ramblings, so I am mentioning it again…

For those of us in the Northern Hemisphere, today, 13th December, (or tomorrow, depends on the number of years since the last leap year) is the day when the evenings start drawing out, which personally I find a relief as going home in the dark depresses me. Sunset tomorrow will be later than today – by all of a few seconds but, heck, later is later. I cannot say for sure I suffer from Seasonal Adjustment Disorder (SAD), I just know I hate spending all the daylight part of the day in  a freeking office.

However, as many of you are probably thinking, shortest day in the Northern hemisphere is not until the 22nd December (it’s the 21st or 22nd, depending on how long ago the last leap year was – again). Mornings continue to get later until around the 3rd January but evenings are already stretching out. Why?

It is because the length of the astronomical day is shorter in our winter than in our summer as, oddly enough, planet Earth is closer to the sun when the majority of humanity, ie those of us living in the Northern Hemisphere, have our winter. Our clock day is fixed at 24 hours as that is the average over the year. But during December our solar day (sun-at-highest-point to sun -at-highest-point) is shortest. I explain more in This post here . Added to this, the earth is not “standing totally upright” in its orbit. If you think of the plane in which the earth circles around the sun as a flat surface, the north pole is at the top of the planet and there is a pole sticking though the earth that it spins around every day. that pole is leaning back away from the sun today and slightly to one side, like a staggering drunk. Because of that we see this odd wobble of closest-to-the-sun and mid-winter and a few other things. Go back to my original post, linked above, as I added some clarification there.

For the timing of sunrise and sunset for the city nearest you, check out this nice website here. This link will show London but you can change that.

The original post is here. It does not say any more but there are a couple of pretty sunset pictures on it.

Of course, if you are in the Southern Hemisphere {say Perth, Australia} then your sunrises have just started getting later by today. But time for the Barby in the evening is still drawing out for a week or two. We can all be happy 🙂