The Time Zone System Gone Wrong: Causes, Problems and Fixes

You've probably already heard of time zones - they are intended to keep local times around the world close to local mean time, ensuring solar noon falls as close to 12:00 as possible, without compromising the use of UTC (Coordinated Universal Time). But let's face it, when it comes to actual usage, the time zone system has unfortunately gone awry. What are the causes of this, what problems does it have, and how can we potentially improve the time zone system? We will give answers to those questions in this blog. Without further ado, let's get into it.

Before we talk about anything else, I just want to elaborate on how the current time zone system has "gone wrong", in case you didn't know already.

Basically, for any place on Earth, there are two versions of "local time": there's a "clock time", and there's a "local mean time". There is a difference between the two:

- In "local mean time", solar noon (the moment the sun reaches its highest point in the sky) occurs at 12:00 on average.

- In "clock time", however, the average time of solar noon may not be exactly 12:00. (When the term "local time" is used unqualified, it generally refers to this version of local time.)

This is because the "clock time" of a location is the "local mean time" at a specific "reference meridian" (a meridian is a line of longitude or, in mathematical jargon, a locus of points with the same longitude), which in most cases does not pass through the location. This is for the sake of convenience, but at the same time it gives up some accuracy. The exact average "clock time" of solar noon depends on the difference between the longitude of the local meridian and that of the chosen reference meridian; the bigger this difference, the farther away from 12:00 "solar noon" will be on average.

Any meridian may be used as reference, although multiples of 15 degrees are recommended because their local mean times are a whole number of hours apart from GMT/UTC. This can potentially make local times more unified across a larger area without giving up too much accuracy, and also facilitates the conversion between UTC and local time. Most places have followed the "15 degrees" recommendation, forming the basis of the current time zone system. Yet, that's not where things have "gone wrong".

Ideally, countries and regions should use reference meridians that are fairly close to their local meridians, to keep solar noon near 12:00. However, because any meridian may be chosen, and for various reasons (to be described below), many countries and regions have opted for meridians that are quite far away from their local meridians, producing inaccurate local times, thereby causing the time zone system to go "wrong".

Now let's dive into the reasons behind the current, far-from-ideal time zone system. When time zones were proposed, they were envisioned to be used ideally. That is to say, the world is divided into 24 time zones, each spanning 15 degrees of longitude. In reality, however, the choice of time zone is often influenced by a variety of factors, including economic and political considerations, as well as international relations, in addition to location/longitude.

- Economic considerations: Some places may choose to use time zones that are ahead of local mean time in order to produce longer evenings (similar to Daylight Saving Time), to the benefit of certain industries favoring more daylight such as tourism.

- Political considerations: Some countries and regions may adopt a single time zone despite them spanning many degrees of longitude, in order to facilitate political affairs. The most notable example of this is perhaps China, which spans over 50 degrees of longitude but nonetheless uses a single time zone for the entire country, namely GMT+8 or China Standard Time. This results in solar noon occurring near 2 or even 3 p.m. in the westernmost parts of the country.

- International relations: Sometimes, countries may choose to use the same time zone as their neighbors, so as to potentially strengthen international relations. Some examples of this are France and Spain, which use GMT+1 or Central Europe Time, even though their longitudes are more westerly than 15 degrees east. In places like Paris and Madrid, it's not uncommon to see solar noon fall around 2 p.m. in summer, thanks to the combined effect of their choice of time zone and Daylight Saving Time. Even when DST is not in effect, solar noon still falls near 1 p.m. in those places.

In summary, a variety of factors, including the ones mentioned above, cause some countries and regions to adopt time zones that are not geographically accurate for their longitude.

Oh well, that's going to complicate things. Daylight Saving Time (DST), or "summer time" as it is called in the UK, does nothing but makes the (already imperfect) time zone system even worse. In case you didn't know, the basic idea of DST is to move clocks forward by an hour during summer, to reduce the need for lighting and thus save energy. Not that I don't support energy saving, but it should be done the right way. Daylight Saving Time moves sunrise and sunset to a later clock time, but more importantly it also makes clocks less accurate in reflecting local solar time, making it a poor choice when it comes to reducing energy consumption.

Since we are talking about time zones, DST will not be discussed in detail in this blog. In fact, DST alone could make for a whole blog, but that's not the main topic today.

You may be wondering, what problems will arise if clocks are not well-aligned with solar time? Well, all sorts of problems. In this section I will be talking about some of the biggest ones.

The first problem is the alignment of solar noon with local time. If you are on a local time that's not geographically accurate, then chances are solar noon will occur relatively far away from 12:00 on your clock. This goes against the basic principles of clock time. Think about it: Have you ever referred to 12 o'clock as "noon"? Most likely yes. But how does that make sense if 12:00 is so far away from actual noon in your area?

Another problem is found in your daily life, which is based around clock time. If you are on a local time that's ahead of local mean time, you are effectively getting up and going to sleep earlier. Similarly, if your local time is behind local mean time, then you'll be getting up and going to sleep at a later time. This can cause your daily routine to be misaligned with the sun, which in turn may have health implications.

Also, in some cases, inaccurate clock times may lead to extremely late sunrises or extremely early sunsets. This once happened in Moscow, Russia. Basically, they were adopting permanent DST, which means setting clocks to a time zone that's about an hour ahead of standard time all year long. More specifically, they were on GMT+4, while Moscow is located near 38 degrees east! At the end of December, around the winter solstice, the sun did not rise until about 10 a.m., well into the working hours. As a result, that winter was described by locals as the "darkest on record".

Now it's time to discuss the ways we can fix, or improve, the time zone system. Please note that these fixes are for reference only.

The simplest and most ideal fix one can think of is perhaps to use time zones as originally intended. In other words, there would be 24 total time zones in the world, each of which would span exactly 15 degrees of longitude. Each time zone would be on a local time that's a whole number of hours apart from GMT/UTC, and centered on a meridian that's a multiple of 15 degrees. For example, the time zone GMT+8 would be centered on 120 degrees east and span the area between 112.5 and 127.5 degrees east.

In this envisioned time zone system, every single point on Earth would have a local time that's no more than 30 minutes apart from local mean time. But, it's easy to notice that this proposal is highly impractical and extremely challenging to implement. For instance, a city may be situated on the edge of two time zones and therefore may need to use two local times. Needless to say, that would do nothing but confuse the city's residents, causing all sorts of ambiguity, with questions like "is it 2 o'clock or 3 o'clock" all over the place. Here's a more practical fix:

- Have smaller countries adopt a single time zone based on the capital city's longitude;

- For bigger countries spanning many degrees of longitude, have each first-level subdivision of the country (e.g. U.S. state, Chinese province) adopt the most geographically accurate time zone for their longitude.

It is worth mentioning that this proposal may also face challenges in implementation, including the factors mentioned earlier in the blog. Having said that, nothing is impossible. As long as more people start to recognize the problems associated with geographically inaccurate time zones, there's a chance that national and regional governments may be influenced by public opinion and end up adopting more accurate or "better" time zones. It may be challenging, but change is definitely possible.

I am a strong advocate for geographically accurate time zone choices. In my opinion, the accuracy of civil time should not be traded for social, economic, political or diplomatic benefits. Many people want "noon" to be as close to 12:00 as possible, and it would be a good idea to listen to them. Actually, time zones themselves already aim to strike a balance between accuracy and convenience.

There's also this thing called "Daylight Saving Time", which again trades the accuracy of clock time for social and economic benefits. As I mentioned earlier, that's not the main topic of this blog, but it's certainly something I think needs to be scrapped to achieve the goal of more accurate local times around the world.

Thanks for reading.