# A Call to Get Rid of DST... and Time Zones

2023-11-04 - [52] 8:19

It's that time of year in the US again, where we set our clocks back an hour. Sure does suck having to find all of the wall clocks and alarm clocks twice a year. CGP Grey made a very popular video that makes the rounds during these times of the year which is linked below:

"Daylight Saving Time Explained" Youtube video by CGP Grey [HTTPS]

While we're at it, time zones in the modern day suck too... we should get rid of those. A wonderful video by the Map Men is linked below talking about the silliness and arbitrary nature of many time zones:

"The world's silliest time zones" Youtube Video by the Map Men [HTTPS]

## Replacement for DST

There is argument in the US at least as to whether we should stay in Standard Time year or stay in Daylight Time all year. While the more popular position in the US seems to be staying in Daylight Time all year, I'm a fan of staying in Standard Time all year to match up the time better with the Sun. There is more to this post though, as we still need to discuss time zones...

## Replacement for Time Zones

We actually have an excellent solution already for keeping time standardized that doesn't involve time zones. That solution is called UTC, which stands for "temps universel coordonné" or "coordinated universal time"... Yes, UTC does not fit either of those and was a compromise between French speakers and English speakers, seemingly to make everyone wrong? Something about "meeting in the middle" meaning "we're all going to be wrong then" entertains me a little bit.

Okay, fine... we all switch to UTC and then all have the same time. Setting up meetings will be easier, especially in an age where we're more connected than ever before, but what are we going to do about some places waking up at 02:00 while other places wake up at 16:00?

## Let's use sundials again!

Assuming we go with the idea of getting rid of time zones and using UTC instead, we are now freed from strictly needing to match the time of places decently far away. For things that need precise times, we have UTC, but for local things, we can use the local solar time. Yes, this means sundials will be useful again.

Time used to be considerably sloppier than it is now, where 6am was about 6 hours before solar noon and 6pm was about 6 hours after solar noon, but nothing was really exact. That big deadly laser in the sky was what dictated the time and clocks were used as an approximation of that time. When the clock showed noon, you knew it was around noon, but it didn't need to be perfect. For local businesses and locations, that system is perfectly fine, and in my opinion is better than the stress of keeping perfect time.

Some places need to close at specific times though due to laws, like liquor stores and bars in quite a few states in the US. Well, we have UTC to deal with that precise timing!

A baker in town can set their hours for "10 AM - 3 PM Local Time" and people would know it's open about 2 hours before solar noon to about 3 hours after solar noon. The liquor store in town can set their hours for "15 - 03 UTC". The concert a few states away can be set to start at "00:30 UTC" and that hockey game you have been waiting these last few days to watch can be set to start at "01 UTC".

Sure, having 2 time systems does complicate things a little bit, but only a little. It's just a matter of getting people used to UTC in general while also letting those people figure out on their own when solar noon is. A clock at a town square set to solar time can certainly help.

I said just a bit ago that clocks were just an approximation of the time, so let's get into that...

## Equation of Time

The Equation of Time, which essentially means "to make the time even" is an offset of the "actual" solar time from the "average" solar time throughout the year. The average solar time, also known as the "Mean Solar Time" assumes that the Sun moves (yes, I know that the Earth revolves around the Sun, but it's a little easier here for me to talk about the movement of the Sun compared to the Earth) from East to West across the sky at exactly 15 degrees per hour and that a day is exactly 24 hours long. Unfortunately, due to the Earth's eliptical orbit around the Sun and the about 23.5 degree tilt of the Earth in relation to its orbit around the Sun, the actual Sun appears to slow down and speed up at points throughout the year, meaning days are not always exactly 24 hours long. This fluctuating solar time is called the "Apparent Solar Time".

Tom Scott did a video on the Equation of Time, which I link below:

"The Equation of Time: Clocks Vs Sundials" Youtube Video by Tom Scott [HTTPS]

The Mean Solar Time relies entirely on your longitude in relation to the prime meridian (0 degrees longitude), where every degree East of the prime meridian sets noon to an additional 4 minutes before 12:00:00UTC and every degree West of of the prime meridian sets noon to an additional 4 minutes after 12:00:00UTC. For example, a longitude of 101 West will set noon Mean Solar Time to 18:44:00UTC and a longitude of 67 East will set noon Mean Solar Time to 07:32:00UTC.

Figuring out the Apparent Solar Time relies on knowing an offset for the time of the year. This offset is called the Equation of Time.

In case someone wants to go through "Astronomical Algorithms 2nd Edition" by Jean Meeus on their own and calculate the Equation of Time for a particular moment, I will include the needed information directly below. Unfortunately it was an absolute pain in the butt for me to find this information online, so maybe this will be useful to someone else who might find this...

- To get the eccentricity component, solve the Sun's Equation of Center from page 164 and multiply that value by -1.
- To get the obliquity component, find the "true" longitude of the Sun by adding the value of the Sun's Equation of Center (we don't multiply it by -1 this time) to the Sun Mean Longitude, whose formula is found in section (28.2) on page 183. Subtract the Sun's right ascension from the Sun's "true" longitude to get the obliquity component.
- To get the equation of time offset, add the eccentricity and obliquity components. Remember that 1 degree is equal to 4 minutes of time.

### Gregorian Calendar

The data for this graph was collected by averaging the eccentricity and obliquity components at 12:00:00UTC of each day at longitude 0 for Gregorian Calendar years 1951 AD through 2100 AD. I ended up using the day-of-year, starting from 1 and ending at 365, to make the averages. I skipped the 366th day of the year (December 31st) on leap years to keep the year graph data to 365 days. To get the eccentricity and obliquity components, I used my program "Syzygy", which uses formulas written in Jean Meeus's "Astronomical Algorithms 2nd Edition". The Git repository for syzygy is linked below.

Syzygy Git repository [HTTP]

### Limerick Calendar

Some folks might know that I fancy myself as somewhat of a "calendar nerd"... So much so that I made my own calendar system, which I call the "Limerick Calendar". It is a 5 day week calendar rather than a 7 day week calendar. More info can be seen at the limerick calendar wiki page, which is linked below.

{limerick calendar}

Anyhow, here is the Equation of Time graph for the Limerick Calendar.

Just like my Equation of Time graph for the Gregorian Calendar, I averaged the eccentricity and obliquity components at 12:00:00UTC of each day at longitude 0. This time I collected the data for Limerick Calendar years [-21] through [128]. I used the day-of-year, starting from 1 and ending at 365 to make the averages, just like I did for the Gregorian Calendar version of the graph. I skipped the 366th day of the year (12:36) on leap years to keep the year graph data to 365 days. The slight differences in the Gregorian and Limerick Calendars is why the pixel data is slightly different, especially because the skipped day from leap years is different between the two calendar systems.

## So what do I do?

It would feel weird for me to talk about how we should switch to UTC and local solar time without using those systems myself.

I use UTC for my time on my watch, desktop computer, and laptop. I also include the solar time on my watch and desktop computer. I have only included the solar time on my watch and desktop computer since about August 22nd though. Before that, I was using UTC by itself.

## Extra

I didn't know where else to put this. The Science Asylum and Mr. Beat did a collaberation discussing time zones. I recommend watching both videos.

"Why Do We Have Time Zones?" Youtube Video by Mr. Beat [HTTPS]
"A 'Day' Isn't What It Used To Be" Youtube Video by The Science Asylum [HTTPS]

## Contact/Reply

If you would like to reply to this post, feel free to send me an email.

Email: vi@vigrey.com [Email]
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