Every person has his own individual sleep behavior. It is dependent on our genetics and is not changeable. So it is in nature that some people sleep longer in the morning, while others get tired in the evening faster. These sleepingtypes are also called "larks" and "owls". This different sleep behavior, which is also referred to as "circadian rhythm", often does not fit in with the timetable set by society. Especially late risers often fight with the so-called social jetlag, as they tend to become more active in the evening and therefore can not fall asleep until the late hour.


Social jet lag is comparable to jet lag, which we experience in a different time zone, but the affected person often accompanies a lifetime. This, in turn, has far-reaching consequences for health and performance because our body and our psyche are indispensable to proper sleep. The limitation of performance is reflected in the work, motivation behavior and attentiveness and leads to frustration and in special situations, such as driving, even to dangers.


In this project, I designed a watch that not only represents the omnipresent numeric time but also the individual inner rhythm of the wearer. For this purpose, this recognizes various body characteristics of the wearer with the help of sensors which are located on the watch.



A special challenge in the design was the representation of the circadian rhythm. It has to be recognizable and displayed in relation to the real time, but is also a very personal piece of information that is not intended to be shared and therefore should not be visible to outsiders.


Over numerours concepts, drafts and research I developed a solution, which shows up the twelve different watchnumbers with divergent opacity levels. The opacity levels show the wearer's degree of alertness, to visualize the tired and awake periods of a day.


To preserve privacy, this is only shown when the wearer covers and shadows the display of the watch. This moment of darkening the watch is a special and intimate situation for the user because by covering the clock the wearer prevents another person from seeing what happens on the dial.