Astrapo’s comment yesterday about extreme latitudes is perfect timing for today’s astronomic equinox.
Today's pattern of sunlight (top image, as of a few minutes ago) is centered onto the earth and is moderate even at the extremes of the north and south poles. But just two months ago (below, at about the same time of day), it was near-continuous dark at the northernmost latitudes; it was dark even longer during the December solstice. Things get squirrelly when diurnality and nocturnality collide … so get ready, southern hemisphere!
You can keep an eye on the daily and seasonal sunlight patterns through the blogroll link to the World Sunlight Map.