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During 2021, my #allsky camera took an photo of the sky from the Netherlands every 15 seconds. This image combines the 2.1 million images into a year-long keogram, showing the length of the night change during the year, the motion of the Sun and Moon, and lots and lots of clouds. 
In a keogram the pixels along the local meridian, the line along the sky from South to North, are plotted against time, as shown in this video. Keograms were developed for the study of Northern Lights, see blog.aurorasaurus.org/?p=1229 for more information.
During a clear night and day, a keogram will show the stars move through the meridian, with the constellations mirrored left to right. Here is the keogram for February 2nd, 2021, with the constellations of Orion, Ursa Major (Big Dipper), Leo, Bootes, Auriga and Taurus labelled.
