I thought the winter solstice would be an appropriate time to make another one of these graphs, and here it is.
To build this graph I collected about 40,000 thumbnails of photos that have been tagged â€œSunsetâ€.
I positioned each thumbnail horizontally according to the day it was taken, and vertically according to the hour it was taken.
By making each photo translucent, I created a â€œhot spotâ€ which shows when the most photos were taken, each day of the past year.
The bright band shows the approximate time of sunset for each day for most of the photographers (who are in the northern hemisphere). You can see that as the year progresses, the time of the sunset changes.
The deepest dip in the band corresponds to the summer solstice (about June 22), and the high parts on each end correspond to the winter solstices (about December 22).
The photos which are not in the bright area are anomolous for various reasons. They may not be photographs of the sunset or they may have incorrect time information in the metadata.