Sunday, 20 June 2010

Come back Mr Sun

As we approach the Winter Solstice (20/21 June) I thought I'd check my GPS to see what it had to say about sunrise and sunset times. I always expect that after the winter solstice the sun will rise earlier and set later... but it doesn't quite happen like this.

This is the definition of the winter solstice from Wiki (I've edited out northern hemisphere references):

The Winter Solstice occurs exactly when the Earth's axial tilt is farthest away from the sun at its maximum of 23° 26'. Though the Winter Solstice lasts only an instant in time, the term is also colloquially used as Midwinter. This occurs on the shortest day and longest night, and the sun's daily maximum position in the sky is the lowest. The seasonal significance of the Winter Solstice is in the reversal of the gradual lengthening of nights and shortening of days. Depending on the shift of the calendar, the Winter Solstice occurs on June 20 or 21 in the Southern Hemisphere.

The times below are taken from my GPS and refer to sunrise and sunset where I live in Jo'burg.

On 21 June, the sun starts to set later. Finally, the clock reverses and the sun goes to bed one minute later, at 17h24 (sun rise at 06h54). I'm looking forward to it not being dark by 6pm...

But, it is only on 13 July that the sun starts to rise earlier - 06h54 vs latest time of 06h55. Sunset on 13 July is 17h31.

It's only in later August that things start to speed up and that every day the sun sets later and rises earlier.

Tick-tock-tick-tock... we're not even fully in winter; already I long for daylight to have more length. I wouldn't do very well living in Norway!

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