Ham radio follows the seasons. In the dead of winter, we work the low bands working with the darkness to carry our signals around the planet. In the summer, we blissfully talk into the night, our signals carried on the high bands basking in the light.But, from a contesting viewpoint, winter and summer are poor times to contest on all bands. The reason: the light and dark times are very different in each part of the world. Consequently, there is built in bias to the different parts of the world for working the bands.No, the best times for a contest on all bands are when the the sun is right above the equator with equal day and night around the world. All bands are in play the same relative time during the 24-hour day. Propagation evens out to match the evenness of the sunrise and sunset.Do you have access to a grey line program? On many, the program allows you to change the time and season to see how the grey line looks. Taking a picture of the grey line at a summer solstice or an equinox clearly shows this propagation difference.Here is a picture from the summer solstice with the sun it's furthest north:You see how narrow the darkness area is in the northern hemisphere? And the darkness is spread out in the southern hemisphere because the sun is so far north. Antarctica is dark all day and the Arctic is the land where the sun never sets.Contrast that with the spring or fall equinox grey line:See how square the darkness area looks now? At the spring and fall equinox, all bands in all parts of the world have equal propagation.And that makes a contest fair. At least as far as propagation on a band goes.Scot, K9JY