# Sticky  A Short Essay On the 24 Hour Watch



## Red Rover

*An Essay on the 24 Hour Watch *

The 24 hour watch dial, known and used historically in aviation circles, is lesser known to those who use a 12 hour watch or clock to tell time every day. I recently learned about the existence of 24 hour watches. Now that I have been exposed, I have doubts that I can ever go back to telling time with an instrument that must hit each number on the dial twice during a "day". Or at the least, I'm not sure if I want to. For me, the 24 hour watch is a thing of simple beauty; the problem is I have spent 53 years telling time using the ingrained memory of a 12 hour dial. There are new things to learn. 

This essay will only consider the true 24 hour watch on which the hour hand moves one full revolution in a twenty-four hour day. By definition, a 24 hour dial has more information to convey, and can appear more cluttered, than a 12 hour dial. There are twice as many hour indexes to squeeze into the same space. This necessitates them being placed much closer together and puts hour indexes in locations on the dial where we are not used to seeing them. This requires careful design by watchmakers, and applied knowledge by the watch user, to be able to tell the time proficiently. "Proficiently" may sound like a strange word to use to describe telling time, but the 24 hour dial requires the user to acquire new knowledge of the landmarks or reference points that define time on the dial to use it without having to work at it.

The most important reference point on a 24 hour watch is "the top", or what we normally refer to as 12 o'clock on a 12 hour dial. On a 24 hour dial, the top is typically denoted with the 24 or 12; the 24 referring to midnight and the 12 referring to noon. Some watches may use 00 in place of the 24. We could have a whole discussion about "24 is really 0000", but we can argue that on a different day. For now, I will use 0000 to say the time at midnight, and 0001 for a minute past, but 24 is the index on the watch. 

Here are two styles of 24 hour dials; a 24 on top (blue), and a 12 on top (black); both photos from the Glycine web site:



















The number "at the top" describes the style of the 24 hour watch, so I'll refer to it as the *base index, *12 or 24.Both styles have 0600 and 1800 at what we know as the 9:00 or 3:00 on a 12 hour dial. I'll refer to the 9:00 o'clock position as the "left side index" and the 3:00 o'clock position as the "right side index". Eventually, we need to get away from references based on our knowledge of the positions on a 12 hour dial and see the watch in a whole new way. We're not there yet, though.

It helps to visualize the dial in two halves, a top and a bottom. On a watch with 12 on top, also known as a purist, the left side index starts the sequence of times at 0600 and the right side index ends it at 1800. Advancing clockwise from the left side index are 0700, 0800, 0900 &#8230;&#8230;&#8230;. on to 1200 at the top, then to 1300, 1400, 1500&#8230;&#8230; and ending up on the right side index at 1800. 0600 and 1800 are the 24 hour equivalents of each other; 6 a.m. on the left and 6 p.m. on the right. I'll refer to them as the "companion times" of each other. Companion times are always twelve hours apart and directly opposite of each other on the watch dial.

Continuing clockwise past 1800, each hour index is a companion time of its counterpart from the top half of the dial. For example, 1900 is the companion time of 0700, 2000 is the companion time of 0800 &#8230;&#8230;&#8230;. 0500 is the companion time of 1700, and finally back to 0600. All twenty-four hours are denoted once, and the hour hand only hits each index once, in a single revolution of the watch dial. This is the key feature of telling time this way. 

If you can visualize this concept, you will see that on a watch with 12 on top, the top half of the dial is comprised of "daylight hours" and the bottom half of "nighttime hours". This is actually an intuitive part of the 24 hour dial. Day over night; top over bottom, half and half. With a 24 at top watch, the night is over day, but the concept is the same. Some watches, like the blue Glycine above, use a darker color on the dial half for nighttime, or divide the bezel into two colors which can be used to denote day and night hours. Some prefer this design, but it is not required once the concept is understood.

Study the graphic of a 12 on top dial below and note the positions of hour indexes that are in locations that are not familiar to us. Notice that 0600 and 1800 are nowhere near where we expect to find 6:00 o'clock on a 12 hour dial. In fact, there are only three indexes that will be anywhere near where we have learned that they should normally be. These are the base index on top and the two indexes on either side of it. The "on top" is exactly where it is expected and the other two are close, but slightly off. In this case, 1100 and 1300 are near where they are expected, but a little closer to 1200 than normal. The indexes are squeezed closer together so that 13 numbers fit in the top half of the dial. Without utilizing this knowledge, it would be easy to misread 2000 as 4:00 o'clock. 











12 hour dials are frequently referred to as being more "intuitive" but nothing could be further from the truth. We learn the hour index positions as children and they become ingrained in memory until we can tell time on a 12 hour dial that doesn't even have any indexes. There are four primary indexes on a 12 hour dial; 12:00, 3:00, 6:00 and 9:00. These indexes are "straight up and down" or "straight side to side" on the dial. I'll call them "up and downs". Between each pair of up and downs are two other hour indexes. For example, between 12:00 and 3:00 are the indexes for 1:00 and 2:00. Between 3:00 and 6:00 are the indexes 4:00 and 5:00, and &#8230;. and on around the dial.

It is easy to recognize when the hour hand falls on an up and down index or on one of the in-between indexes. This is not intuition, but merely rote memorization of the points and familiarity with the location of the hands relative to these positions. The same thing goes with the minute hand. The distance between each index, is 5 minutes. At a glance, we can tell the time on a watch that has bold lines for the hour indexes and finer lines for minutes in-between the hour indexes. We don't even need numbers because we have learned all the positions. We need to apply this concept to the 24 hour dial to tell time "intuitively" based on the positions of the hands relative to a larger number of reference points. 

Use the graphic of the 12 on top dial for this next section. Break the dial down into four quadrants with the reference points of 0600, 1200, 1800, and 0000. In between 0600 and 1200 there are two even hour indexes; 0800 and 1000. All four are even hours, and if they are all marked the same, it is relatively easy to identify 0600, 0800, 1000, and 1200. There are three odd hour indexes in-between the even indexes; 0700, 0900, and 1100. If they are marked with a different shaped index, say a round dot, they are also easy to tell. If the hour hand is in-between 0600 and 0800, then the dot it's on is 0700. If the hour hand is in-between 1000 and 1200, then the dot it's on is 1100. The concept is the same as with a 12 hour dial, the difference is that there is twice the number of indexes to deal with. There is also a relationship between the hour and minute hands that needs to be recognized to determine when it's coming up to an hour or has gone past the hour. This is the same when using a 12 hour dial and we are all familiar with the concept. 

Watches, like the Glycine Airman, that use lines for the even indexes and dots for the odd indexes help facilitate time reading without visible numbers. The Glycine has small numbers, but they are not always visible. This should not inhibit the ability to tell the time "proficiently". Some Airman models don't have an index for the odd hours, just the number. Watches like the Aviator 24 Hour that use large numbers for every even index and unmarked lines for the odd indexes accomplish the same thing in a different way. The Aviator may be easier for the new 24 hour dial user because the lumed numbers are visible even in the dark. 

Some designers get creative and use different index patterns that may omit one or more key reference points in a section of the dial. This can make it difficult for the new user of a 24 hour watch. Omitting one index, like the 1800 on my Glycine, where the date window is does not cause much of an issue. This is especially true since it occurs at a main index that is easy to identify, one of the "up and downs". 

Examples of some other 24 hour dials (from russia2all.com): 




























This has been a very basic attempt to pass on what I have learned in the past three days since acquiring my first 24 hour watch. It has given me a new found interest in the delineation of time and I am having fun with it. There are watches that have 24 hour dials with regular 12 hour hands and a single 24 GMT hour hand. Those are a whole different topic for discussion and beyond the scope of this essay. Thanks for reading.


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## KevinAbraham

Loved the essay !! Great job and I hope that you enjoy the wearing it 


I have one question though, How do you tell the minutes on a 24 hour watch ?


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## Red Rover

KevinAbraham said:


> Loved the essay !! Great job and I hope that you enjoy the wearing it
> 
> I have one question though, How do you tell the minutes on a 24 hour watch ?


Minutes are the same on a 24 as a 12; there are 60 in one revolution. Look at the white watch above. It is fairly simple, because the hour indexes for the odd hours are unobtrusive, yet they are there to read the odd hours. They don't interfere with reading the minutes. The even hour indexes corespond to the hour indexes on a 12 hour dial, and are the minute indexes for the multiples of 5. There are 4 small indexes for the minutes in between them.

Other 24 hour dials are not as easy to read the minutes on. You sometimes have to develop your own system based on the particular dial.


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## Dennis Smith

Some designers try to make the minute track very easy to read. Here's a picture of one of my old AirNautics. As you can see the minute hand has its own references (the outer track in yellow) while the smaller 24 hour hand has its own reference (the inner track in white).


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## JohnnyBlazE

Fantastic stuff! I may have to get a 24 Hour Watch as I have not owned a pure 24 Hour Watch before.

My Skyhawk A-T's main dial is a 12 hour time scale, with a UTC 24 Hour Watch as one of the smaller dials shows UTC in 24 format, plus the small eye on the right shows the current, analog time in 24 our format:


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## Zennmaster

As a dedicated 24-hour, or as I prefer to call it, "Full-day" watch user, I am often asked "But how do you read it?". My simple answer is: "How do you read a 'half-day' watch?" For the vast majority of people, one's day follows a single cycle: Something on the order of:

- Wake up.
- Have Breakfast
- Go to Work
- Lunch Break (Eat lunch)
- Go home
- Have dinner
- Evening ritual (Kids to bed, evening movie or TV, whatever you do at night)
- Go to sleep

Notice that each of these things happens _once per day. _So why does everyone insist that intuition suggests that a clock or a watch should go around _twice_ per day? It seems to me that we live on a 24-hour cycle, so why should we tell time on a 12 hour cycle?

Of course, I am in the U.S., where apparently nobody expects anyone else to be able to count to 24, so this might be a moot point. I also work in a profession where simply saying something like "6 o'clock" is completely insufficient, so maybe I'm not the best guy to ask.

Anyway, very nice essay!

And to my friends at WUS: Great to be back, how y'all doing?!


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## Dennis Smith

Michael! How are you, my friend?
Good to see you here.
Hope all is well.
I'll be passing through Portland sometime in early December.


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## Zennmaster

Dennis Smith said:


> Michael! How are you, my friend?
> Good to see you here.
> Hope all is well.
> I'll be passing through Portland sometime in early December.


Hiya Dennis!

I'll be around from the first to the 7th, drop a line if you have a minute!


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## mark44

Glycine is refine quality watches. Best thing I found is your resemblance of watches with aviators. 
I always love to put my glasses and watch on.


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## jennyasdf94

I was one who didnt like 24 hours watches...but now i am changing my mind and want to buy one. 
Although its seems to me like a stop watch we use to calculate time in school during experiments in lab.
We had a stop watch just like this one 







The only difference is this one has a strap with no stop and start button but that one had.
Tick tokk...we used to play it some time 
Any one suggest any model for 24 hours watch?
I couldnt find one. I found some but sites places IDs rather than the model names.


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## TabascoTodd

OP - Thanks for this great essay. I enjoyed reading it.


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## asphericalperspective

Very interesting read. 24-hour watches definitely have their appeal. 

I have a couple of questions though (not necessarily directed to the OP, feel free to answer): 

1. (I'm assuming you own both 24- and 12-hour watches) Do you find it confusing to switch back and forth? Or do you only stick to 24-hour watches? 

2. Can you give your opinion on these Russian watches? The first one (black Aviator) looks great. Any opinions on its movement/quality? 

Cheers!


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## cybertrancer

Hi Eddie! b-) 

1 - For me it is not confusing maybe because here where i live we are used to a 24h scale (radio, tv, newspapers etc). For me it makes more sense a 24h scale watch because the day has...24h! :-d
I also work in shifts so it makes even more sense to me. I also own 12h scale watches and i don't find it difficult when i switch from one to the other.

2 - I own one of those black PVD Aviator watches. It is very sturdy. Daily rate is around -10s to -15s a day. Movement is the hand wound Poljot 2623. From the official homepage they now use the hand wound Plojot 2614. Difference should be minor (try looking at the Russion forum for more info on these movements).

I hope this helps!


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## asphericalperspective

Cybertrancer - Thanks for your reply. I will do some further research in the 24-Hour/Russian Fora


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## Red Rover

asphericalperspective said:


> Very interesting read. 24-hour watches definitely have their appeal.
> 
> I have a couple of questions though (not necessarily directed to the OP, feel free to answer):
> 
> 1. (I'm assuming you own both 24- and 12-hour watches) Do you find it confusing to switch back and forth? Or do you only stick to 24-hour watches?
> 
> 2. Can you give your opinion on these Russian watches? The first one (black Aviator) looks great. Any opinions on its movement/quality?
> 
> Cheers!


I don't find it confusing changing between 24 hour and "normal" watches. Once you teach yourself how to read your 24 hour dial, 12 up or down really doesn't matter to me, it becomes easy.

I had 1 Russian (can't remember which) that I sent back because it didn't seem very rugged. Many like them and they are certainly less expensive than a Glycine.


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## cooma

Good essay! I did order Russian 24-hour dial watch few days ago so this is theme forum is usable for me now.

These 24-hour dial watches are useful as a compass, when the Sun or shadows are visible! For example if 24-index is on the top, you can turn your watch so that a hour hand is pointing toward sun. Then the north is in direction of 24, south is in direction 12 etc. Daylight saving time affects this by one hour and you can correct this by remembering that the sun time is one hour less.

Of course you can use ordinary 12-hour watch similar way, but it is more complex (you can check for example a manual of a Seiko Alpinist). I have used a watch and the Sun as a compass several times. For example if you are travelling and you come out of a subway station, you must know a direction of the north before you can read a map. Using watch and sun is usually quick way to find those directions.


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## cooma

I have used a watch as a compass sometimes in the way described above. 24-hour watches are very easy to use in this purpose. However I was wondering how accurate this method actually is, so I decided to calculate it. Besides I have never used a math program Octave and this was a good excuse to try it.

A direction of a shadow can be described as a local projection on the surface of the Earth. The local surface is a plane defined by unit vectors:
















(explained for example here: Spherical coordinate system - Wikipedia, the free encyclopedia)

I choosed a coordinate system so that the Sun is shining to the direction of x-axis and the z-axis is perpendicular to the plane where the Earth is moving around the Sun. The axial tilt of the Earth is 23.5 degrees and the tilt looks like it rotates around z-axis in the choosed coordinate system. I used rotation matrices Ry and Rz (described here: Rotation matrix - Wikipedia, the free encyclopedia) to simulate it.

And now to the results. I calculated an error angle from the real compass direction. Basically "a watch compass" works better near to poles than near to the equator. At latitude 60 degrees where I live it works pretty fine (0 degrees in equator and 90 degrees in the north pole):










The biggest error lies in summer time. The middle point is in a summer.

This is a closer look at the daily variation in winter, when day light time is quite short:










The same in a summer time, when daylight time is quite long:










The above 15 degrees error is certainly tolerable. Compare to the common 12-hour dial where the angle between hour indexes is 30 degrees.

In the nearer to the equator in a latitude 30 degrees the error is bigger. It is still usable as a rough approximation for example to set a map in right position before reading it. I quess that bigger error in summer is caused by the Sun is even higher in noon and the shadows are very short:










In a "winter" time:










In a "summer" time:










In above pictures curves is drawed only when the Sun is visible. In a north, for example in latitude 60 degrees, the Sun is shining almost over night in a mid summer, so it is more usable then.

There is couple more small error sources besides the axial tilt angle and the latitude. The Sun time is max 15 minutes different to a local time because of the orbit of the Earth is elliptical which is equal to a max 7.5 degrees error. Also the local time zone is divided in one hour resolution which is equal to a max 15 degrees error. So this method is usually accurate enough for certain purposes.


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## derelict

Something that I have been curious about. I am contemplating a 24 hour watch. Maybe a single hand, not sure. What I wonder about is how are the movements different than say, a regular 12 hour sweep watch? Or, are they?


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## pley3r

Something like a Vintage Russian Raketa has a purpose built 24hr movement. Basically some different sized gears I believe because obviously the hour hand is rotating at a different rate compared to a 12hr watch.
New watches like a purist Glycine airman use a GMT movement minus the normal 12hr hand. So in effect its a 4 handed movement (normal 12hr plus 24hr GMT) with only 3 hands attached to give you a 24hr watch  If you look side on at the hands on my Glycine there is a larger than normal space between the hour hand and the minute as the 12hr hand is missing in between.


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## derelict

pley3r said:


> Something like a Vintage Russian Raketa has a purpose built 24hr movement. Basically some different sized gears I believe because obviously the hour hand is rotating at a different rate compared to a 12hr watch.
> New watches like a purist Glycine airman use a GMT movement minus the normal 12hr hand. So in effect its a 4 handed movement (normal 12hr plus 24hr GMT) with only 3 hands attached to give you a 24hr watch  If you look side on at the hands on my Glycine there is a larger than normal space between the hour hand and the minute as the 12hr hand is missing in between.


Thanks for the information. The Glycine is a looker and so is the Dreadnought Voyager. Where can one find affordable, like ~$300 24 hour watches? I prefer hand wind but am open to auto or quartz as well, depending upon the design.


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## Dr_X

I found this essay very helpful! Thanks for posting it.


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## mrsgarkenzie

Great article!


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## heb

Thanks for the info. I just figured out, after all these years, why the Glycine hour hand has that long, exaggerated tail--to remind you what the 13 to 24 is in 12 hour time; i.e. "19" = "7". heb


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## Corduroy_Pillows

Great essay, thanks for that. I love 24 hour watches. Some day I'll be able to afford this beauty - Order one-hand & designer watches online


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## peagreen

It has the same problem as a number of other watches: from 15:00 until 09:00 the next morning you have to read numerals that are on their side or upside down.


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## raghu sankar

That was a great essay. But I am still confused. My q&q watch has a 24 hr marking. But instead of taking time to 13 hr , the 24 hr dial starts at 1,2,3 and so on. I could not make out the purpose of this 24hr dial. Please could you enlighten me. See the dial below.


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## raghu sankar

Oops the photo didn't get loaded. Here it is.


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## watchely

very essay !! Great work guys and keep it up


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## UofRSpider

Hey guys. It's awesome to finally find likeminded people that love the 24-hour concept. We've recently been working on our own design and we'll be launching it on Kickstarter soon. We'd love it if you just took a second to search us up and check out our designs and maybe even sign up to receive our updates.










Sent from my SM-G900V using Tapatalk


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## Dixit

Hello everybody,

Coming from f10 I just stumbled upon this forum and this nice essay. Sovjets have a long tradition of 24h watches and Vostok is continuing this tradition.

I just got myself some 24h Vostoks.

The funny part: they are lumed, i.e. the hands are quite well lumed. The index dots are lumed, but only the even digits. I have one Vostok where the digits themselves are supposed to be lumed, but the lume is that crappy that you only see the hands and the dots.

I find that funny. I have become very accustomed in reading 24h watches, but at 3h in the night I am not able to read the time off the Vostok with only the even dots being visible. That needs a bit too much brain power.
On the other hand - as the essay explains it - I can easily and automatically read a 12h watch with only the hands being visible (I don't even need the dots).


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## GulfCoastWatch

Very nice essay. Thanks.


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## laredy26

Nice write up


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## phillyforager

Awesome write up - thanks for this!


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## thegolferguy

Great write up, Thanks for sharing


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## Spirit’dWatcher

Enjoyed the write up too  - if you really want to get your brain dancing add a one hand watch as well ;-)


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## Jonathan T

Having just discovered 24 hour dials while looking at a night and day watch, it was nice to discover this essay as well describing in detail. I hope to acquire a 24 hour watch as my next purchase! Thanks!


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## segibbons03

Good read


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