After a long summer, autumn has arrived. The days are getting shorter; in fact the length of the day has already decreased by 7.5 hours.

When the day lit hours decrease many people, especially in the Northern latitudes where winter hours of daylight are fewer, complain of feeling down. We are hit by the winter blues.

The issue of daylight in buildings and its effect on people is very important, because it places a substantial burden both on individuals and the economy. Therefore buildings need to have well thought out daylight designs which will create healthy indoor climate and save energy at the same time.

Diminishing daylight is getting more and more relevant everyday now. When we reach winter solstice on Dec. 21st the length of the day is decreased by more than 10 hours, but fortunately the daily dose of daylight then start building up again.