What's Wrong with Daylight Saving Time (and Why We Should Scrap It)

Daylight Saving Time (DST), known as "summer time" in the United Kingdom, is the practice of shifting clocks 1 hour ahead of standard time during the warmer months of the year. Countries usually start DST in the spring and switch back to standard time in the fall (hence "spring forward, fall back"). This clock shift can help conserve energy as it puts more daylight into the evening hours, thereby reducing the need for artificial lighting. But as I see it, the benefits of DST pretty much end there. In this blog we will look at exactly what is wrong with Daylight Saving Time, and the reasons why it really should be abolished. Without further ado, let's get started.

Let's take a look at two dialogues between person A and person B, conducted on different days of the year - one on the day before the start of DST, and the other on the day before the end of DST. Note that person B comes from a country without DST and thus knows nothing about it.

From these dialogues, it's not hard to spot one of the biggest problems with Daylight Saving Time. The clock shifts to and from DST can easily confuse people, especially those from countries that don't observe DST.

(An aside: DST in the United States and elsewhere had always confused me until I became aware of it. I once read somewhere that the time difference between Beijing and New York was 12 hours, but later, through the "World Clock" feature on cell phones I found that the time difference was sometimes 12 hours, and sometimes 13. Many years later I finally understood the reason for this, which is Daylight Saving Time. The same happened when I looked at UK time: I've long been aware of GMT, but I once saw the UK being on GMT+1 and wondered why they weren't on GMT, until I learned about British Summer Time.)

It is also easy to see that clocks "jump" at the start and end of DST. Essentially, one whole hour is "lost" when DST begins, and it is not compensated for until DST ends. This makes time calculation more complicated. For example, if DST is starting on a day, then there will only be 11 hours between midnight and noon on that day. Similarly, if DST is ending on a day, then the interval between midnight and noon on that day will be 13 hours instead of 12. Because people are familiar with the regular 24-hour system, it's by no means difficult for them to make mistakes when calculating time intervals near the start and end of DST.

Traditionally, the clock time "12:00" is meant to be placed as close to solar noon as possible (hence the designation "12 noon"). Unfortunately, by moving clocks forward, Daylight Saving Time effectively breaks that tradition. With DST in effect, it's not uncommon for solar noon to fall around 1 PM or sometimes even 2 PM, depending on the location.

Now you may be wondering: how can solar noon be moved to 2 PM if DST only shifts clocks 1 hour forward? Well, the answer lies in the time zone system. The current time zone system is flawed, and DST simply makes those flaws more pronounced by further deviating clock time from local mean time.

The clock changes at the start and end of Daylight Saving Time can prove to be detrimental to your health. This is because time changes can disrupt our circadian rhythms, which are essentially the "clocks" of our bodies. DST changes are no exception: they alter sleep patterns and therefore may have health implications. Since adjusting to the start of DST involves losing one hour of sleep time, it is generally considered higher risk than adjusting to the end of DST, although both adjustments can be harmful.

By advancing clocks, Daylight Saving Time produces longer evenings. People may see this as a good thing for various reasons, such as saving energy by reducing the need for lighting, or making the already long summer days feel even longer (since people tend to deduce the day length based on sunset time only, as far as I know). However, longer evenings are not necessarily good when you think about it. For instance, the temperature is generally higher during the day than at night, and more daylight in the evening can be a bad thing considering the fact that summer days are already hot.

Some people have referred to Daylight Saving Time as "daylight slaving time", due to the fact that it effectively makes people get up earlier every day. While it's a humorous play on words, it does raise a valid point. One implication of DST, alongside producing longer evenings, is darker morning hours. This can be problematic, since people tend to feel better when they wake up during dawn or daylight hours, compared to waking up when it's still dark.

In the northern hemisphere, DST usually starts near the vernal equinox (the last Sunday in March for Europe and the second Sunday in March for the US), but it doesn't end until well after the autumnal equinox (the last Sunday in October for Europe and the first Sunday in November for the US). This imbalance in the start and end times of DST means that there could be very dark mornings just before DST ends.

When Daylight Saving Time ends, clocks are turned back. This means that certain clock times will occur twice on the day DST ends. For example, if clocks go back at 2 AM, then the time on that day will go from 1 AM to 1:59:59 AM, and then - you guessed it - back to 1 AM again. While this is unlikely to cause ambiguity in the majority of the general public (as most people are sleeping when this occurs), it can indeed lead to confusion among people who are awake at that time, such as those working night shifts.

This is basically what I said in the blurb. Some people may feel "tired" of having to manually adjust clocks for DST every year. It's also easy to forget: In November last year, when I was in the UK, I found that a clock was still on daylight saving, probably because people forgot to adjust it when DST ended in October. And I'm sure this is by no means the only case of "forgetting to adjust clocks for daylight saving" in countries with DST.

Nowadays, many electronic devices are capable of automatically adjusting for daylight saving, which mitigates this to some extent. But don't forget, traditional clocks still exist, which is why this continues to be a problem.

Abolishing Daylight Saving Time will benefit us all, and will address most of the problems stated above. More specifically:

Thanks for reading.