How does a time change affect our biorhythms?

The time change, especially March, is a very disruptive time of the year. After months of getting up, going to sleep and doing our homework respecting fixed schedules more or less, a weekend comes and the clock advances us an hour.

Although there are two, March and October, it is the one that starts summer time the one that we all have the most crossed because it is precisely that day when 2 is 3 and, therefore, we have to get up An hour before. There is sleep, fatigue and bad mood.

The way in which the time change affects our biorhythms is something that many of us have surely experienced in our own flesh, and now science has confirmed it, in addition to putting in controversy the need for this practice to, supposedly, save energy. Let’s delve into the debate.

How does the time change influence our biorhythms and associated psychological processes?

The time change, both October and March, is that time of the year that disrupts our schedules a bit (or a lot). It is not fair to talk about both using the same yardstick, because the truth is that, at least in Spain, October is very popular while March is seen as a bad drink, a time change that we do not know. we can escape and that, fortunately, we are lucky that it is done on the weekend.

In the Spanish case, the controversy about the time change cannot be understood without understanding the controversy that exists with our own time zone.. Spain uses the GMT + 1 time zone on the peninsula, while the Canary Islands uses GMT. Spain uses the same system as Central Europe, but not that of its neighbor Portugal or the United Kingdom, which are almost between the same parallels.

The fact that Spain has a schedule closer to Berlin and not to Portugal, despite the fact that it has a region (Galicia) just north of the Lusitanian country has prevented the debate on the need to change the time zone from closing. Among the arguments used to defend and attack the status quo, much is used to the hours of sunshine, the alteration of the biorhythms already well established in the population and the possible economic problems associated with it.


But, let’s focus exclusively on the time change. This practice was established in Europe at the time of the First World War, a time in which the traditional sundials had already been left far behind. With the widespread use of mechanical clocks, which worked regardless of the hours in which the star king deigned to appear in the sky, the way of managing the time of the population did not go according to the hours that there was sunlight.

It is for this reason that it was decided to strategically make two hourly changes per year, in times when the change meant taking advantage of the hours of sunshine. Thus, with the change of October in which we wake up an hour later, we do it because the sun rises later, while in March we have to wake up an hour earlier because the sun is rising earlier and earlier. The time change fulfills its main purpose, to maximize exposure in sunny hours.

But despite the fact that this advantage is fulfilled, the other arguments used to defend its use have been questioned. It has always been said that these schedule changes allow saving, under the logic that if we have work and leisure hours in hours when there is always sunlight, we use less electricity. This idea, however, has long been questioned, with both the European Commission itself and the Spanish Electricity Network indicating that this supposed saving, if any, is minimal.

Given the diminishing evidence that it really serves to save, many have questioned whether this time change is really useful or if it would be better for Spain (and any country in the same situation) to decide to apply a time zone adapted to their geographical condition without need to have to change the time twice a year. The reason for this is that, In a world in which chronobiology is becoming more important, it is becoming clear how the change of time affects our biorhythms.

Alteration of biorhythms

But what are biorhythms? On many occasions it is said that our body has as a kind of internal clock that tells you what to do and when. This clock is the one that “alerts” us when we have to go to sleep, making us feel more tired when night approaches and more alert when there are more hours of sunlight. It is what makes us have established schedules in a totally natural way and that is closely related to circadian cycles.

As the months go by, these biorhythms settle more and more, making us totally used to our routine. The problem with the time change is that there is no “natural” way to warn our internal clock that what was 2 o’clock yesterday is 3 o’clock today and that, therefore, it has to move forward one hour. As it continues with the pre-established schedules, even though the change is minimal, our brain is maladjusted and feels like a kind of “jet lag”.

This jet lag is especially noticeable in the change of summer, that is, the one that makes us lose an hour. Our body has to get used to doing things an hour earlier than it used to, which in many cases usually results in loss of hours of sleep the first few days, this being one of the main effects of the time change. With this we also feel tiredness and fatigue, in addition to some disorientation.

Although the time change rarely involves serious problems, it can be said that certain complications can occur depending on how sensitive the person is to the change and how disrespectful they have been with the new schedules. Some people get to suffer from problems such as stomach problems, mood swings, loss of concentration and, if the loss of sleep is very severe, headaches and migraines.

Contrary to one of the main reasons why it is applied, which is that the time change translates into greater savings and greater productivity, the truth is that taking into account the effects of the alteration of the biorhythm, everything seems to indicate just the opposite. Company workers feel more tired during the two weeks following the change in March, with a higher risk of accidents and lower productivity.

How noticeable the alteration of these biorhythms is depends a lot on each person, but it must be said that age is one of the most important factors. Children, adolescents and the elderly are usually the ones who notice it the most, especially the most baby children and those who are over 50 years old, the change in March being the most difficult to adapt to. Likewise, despite the fact that it is only an hour apart, as a general rule it is difficult for the entire population to synchronize its internal clock with the new schedules.

The scientific community has gone one step further and, although it should be noted that the time change has short-term effects that end up being overcome with the passage of time, the danger of altered circadian cycles has already been known.

We have an example of this in the case of people who work at night or who do not sleep when appropriate, being more prone to suffer from different pathologies such as diabetes, cardiovascular diseases, obesity and, also, psychological problems, including depression and anxiety.

And why is the time change not canceled?

Although there is increasing evidence that the time change changes our biorhythms, canceling it is a complicated issue, especially since it is not only a question of schedules.

Let’s think about the case of Spain, where we use GMT + 1. The reason that we use this spindle, in addition to historical reasons, has to do with our economic relationship with France and Germany, which, if we switch to a different spindle than yours, could have repercussions on issues such as tourism and trade.

Another reason why it has not been decided to cancel it is that, although there are people who are affected a lot, the period of adaptation to the new schedules, although uncomfortable, usually does not last more than 5 days. Although it can be annoying to have to get up an hour earlier in March, and pleasant to do it an hour later in October, as the weeks go by we end up regulating our schedules and coordinate with the rest of society and their time demands.

There is also the fact that there are countries in which if you do not change the time at all, there are regions in which the sun would rise at a few hours that would disrupt anyone’s schedules. Returning to the case of Spain, if in this country we kept the winter time all year round, on the Mediterranean coast it would dawn at 5:00 am in June, while if the summer was continued, the Atlantic coast would not see sunlight until 10.00 am in the month of December.

In addition, you have to try to see the positive side of the time change. Thanks to these two time changes per year we can enjoy more hours of light in the afternoon, which, although it is not so proven that it interferes with energy saving, it is true that most of the population prefers that time of day to dedicate it to leisure and free time, a moment that is most enjoyed with the Sun still in the heaven not in total darkness at night.

Bibliographic references:

  • Dunlap, JC, Loros, JJ, & DeCoursey, PJ (Eds.). (2004). Chronobiology: Biological timekeeping. Sinauer Associates.
  • Cell Press. (2007, October 25). Daylight Saving Time Disrupts Humans’ Natural Circadian Rhythm. ScienceDaily.

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