Normally we promote to sleep at night and be awake during the day. However, Marijke Gordijn from Chrono@Work accepted the invitation to be one of the two guests in the night program De Slapelozen on Dutch radio on early Thursday morning August 12th 2021, between 2 and 4 am. The reason why is that during this program with a beautiful atmosphere, guided by Frits Spits, there was plenty of time to explain the working of the biological clock and it’s role in sleep-wake regulation. The other guest was a photographer, Mischa Keijser ( enscenering wonderful pictures at night by highlighting the object, creating a huge contrast to the dark sky. The combination of art and science, the roles of light and darkness, and rhythms as the central topics created a very special atmosphere in the dark studio. The questions of various listeners who were awake at that time completed the story. In November a television program will follow. If you are interested to listen to the radio program (in Dutch) you can find it here: and