This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Hours of daylight vs latitude vs day of year.svg contour plot of the hours of daylight as function of latitude and day of the year using the most accurate models described in Sunrise equation This SVG is interpreted differently by firefox inkscape and the software provide this SVG version so people can make other versions if they