When the days get colder and the nights longer in winter it becomes harder to roll out of bed in the morning especially when it’s still dark out and that cup of java just doesn’t have that same energizing power to kick start our day. We end up feeling our productivity dissipate as the day progresses and we meet the sunset of our shortened winter day a lot sooner.
Not only does the later rise of the sun in the morning and the earlier setting of it affect us but so does its placement in the sky especially for those who live in the Northern hemisphere. We are affected by what scientists refer to as seasonal affective disorder (SAD). For the few in our northern populations, who experience full-blown SAD it can be debilitating. This condition is hypersomnia which leaves us in low moods and with an overall sense of futility.
For most of us in the northern hemisphere, generally we experience some depression in the winter months but during January and February the rates of suicide increase and daily productivity drops and scientists have linked it to the shortened days of sunlight.
Researchers say the scientific reason for all of that despondency is that our body clocks are not in sync with our waking, working hours. According to Greg Murray, professor of psychology at Swinburne University, Australia, when our bodies are waking at 7:00am, two hours before the sun rises at 9:00am we lose out on getting a complete sleep phase, because our bodies have a built-in clock that regulates sleep and wakefulness in tune to the rising and the setting of the sun. And in the short days of winter, our sleep needs change and the constraints of our modern lives may not be fitting into our need to change our sleep habits during those shortened days of winter months.
Scientists refer to the study of how our bodies regulate sleep and wakefulness as chronobiology and to the ‘circadian clock’ as a scientific concept that measures our internal sense of time – our 24-hour internal timer – that determines when we get up and when we want to fall asleep says Murray.
This is determined by a huge number of hormones and chemicals within our bodies that regulate our body clocks which are impacted by the sun because of photoreceptors which are located in the back of our eyes. They are known as lpRGCs and are especially sensitive to the blue light of the sun during daylight hours and perfectly prime the calibration of our inner circadian clock playing a crucial role in regulating our sleep.
So, scientists recommend, shorter work days to allow for this change in the later rise of the morning sun and its effect on our inner time clocks for the fulfillment of complete sleep phases to provide better productivity during the day, however short those days are in the deepest two months of winter.