nsg's blog

Daylight Saving Time

2018-08-31

I have never liked Daylight Saving Time (DST), It has always been a hassle to change timezone twice a year. I'm off balance for a week and it can be confusing with people missing appointments.

The European Union did have a web based poll going around earlier this month. The exact numbers do not really matters but the spread is interesting with about equal parts of "Remove DST", "Keep DST year around" and "No change".

If we go by the numbers, "Keep DST year around" is a tiny bit more popular and it's considered as a choice. I have opinions about this and this is the primary reason why I write this.

Time Zones

Time zones can be confusing, and if you work with people all over the world it's a large cause of confusion. But the planet is round and spinning and we all do not see the sun at the same time. I'm sitting now at the garden in my summer house in Sweden, that's in central EU, the time is a little after 11am and it's warm and cozy, it's almost the middle of the day with the sun high in the sky. If we go west all the day to New York in USA it's early morning, most people are still sleeping and the sun is about to rise. The time is now considered to be a little after 5am.

It is of course the same time, we are not talking about time travel here. But the idea is to have a local time and a universal global time do make things easier for most people.

A short history of time

In a pre-technological society makes sense to base time after the light. You wake up when the light come, and you goes back to bed when it's to dark to see. The middle of the day is of course the midpoint between the sunrise and sunset, and this is also when the sun is in it's highest point in the sky. To track time with the shadow of the sun is an ancient technology.

Everyone just used the sun to set the time, and this was used even after the clock was invented. Noon was in the middle of the day. Because the planet is round, the suns highest point did not occur at the same time everywhere. Two close by towns may have had only a few minutes time difference, but more distant places would have a larger time difference.

Coordinated Universal Time

The British Empire used time to navigate, they had clocks set to time from the Greenwich Solar Observatory. It's called Greenwich Mean Time (GMT) and is the local mean time observed at the observatory at Greenwich in London.

It's nothing special with this time, it was just the time that the British choose to use and because they where well traveled it has been accepted as a reference time. Later the time was standardized as Coordinated Universal Time (UTC).

UTC is used in most of the modern world, and is base for the different time zones. When I write this, I'm in the time zone UTC+2 with is "two hours in advance of the universal time".

Why we need shared time

In most west countries the invention of the train was a large part of the need of a shared time. Even in a tiny narrow country like Sweden there was a notable difference in time between towns. With watches running on the local time people missed trains because train time did not match local time. For example, a 40 minutes journey starting at 2:00pm will arrive at 2:36pm local time.

If you have traveled with airplanes you probably recognize this, now think about the chaos if every single town, village and other place had their own local time zone. In the old days the small time differences did not matter, but in the modern world with trains and telegraphs it did!

Most countries adapted a standard national time, usually it was the time of the capital. But over the years these time zones where normalized to the modern slices we see today.

Sweden is today part of the Central European Standard Time (CEST) with one hour ahead of UTC (UTC+1), but because it's DST, it's UTC+2 at the moment, Central European Daylight Time (CEDT).

Daylight Saving Time

Now you know why we have different times at different places, but why is this relevant for Daylight Saving time? Daylight Saving Time (DST) was created to optimize the amount of light that people got during the day. By shifting time one hour during the summer months they tried to optimize the amount of daylight you got to see. This better matched the work schedule with the modern worker. I have never understood why the work schedule was not just shifted instead, but I assume DST was an easier fix.

So this is fantastic, more sunlight is good, right? Yeah, there is a small difference yes but most people would not notice this. Sure people notice the first days after the change but that is because people notice changes. Give them a few days and things are back to normal again. But there is a lot of bad things like more people die when we change the time. Farmers hate the change, because the animals do not understand DST, they are just confused when everyone is one hour later/earlier. This is also a little funny because a lot of people believe that DST is for the farmers. Power consumption is higher during DST in large parts of the world, and plenty of productivity and money is lost from tired workers. And then of course, we have the confusing concept of changing our local time twice a year for no good reason.

Final words

It look like DST will be removed in EU next year, nothing is really finalized but currently the suggestion is to let the member countries a choose if they like to stay in Daylight Saving Time or their real original time zones (Standard Time). For Sweden we have the choice if we like to stay in UTC+1 (CEST) or UTC+2. Sweden is nicely aligned with the sun in the UTC+1 time zone so I really think we should keep it, it is our normal real standard time. Then of course, it would be confusing if every country around us choose to keep DST so I guess it makes sense to try to pick something together with the other member states.

I'm really happy that we will stop changing the time for no reason!

Please note that this is a old post from the year 2018 and the information may be outdated. All these 1113 words are written by Stefan Berggren, feel free and contact me if you like.