Time Zones and Time
Remember 853-1212 ?
We rarely think about time zones. We recheck when we travel to understand what the new time zone will be. We inwardly cringe when we forget Arizona and Hawaii don’t use daylight savings time. There are still dumb appliances where we must manually reset the time; they are going the way of the Dodo as phones, computers, thermostats, cars, and other internet connected items automatically reset their times.
But how did time zones come about? And are why are they treated as magical rigid definitions?
How Long Have There Been Time Zones
Time itself has been measured and tracked in a few ways. For most of history, up until the late 1800s, time was based on local solar conditions. This led to small but frequent variations in cities. For example, before England changed to “Railroad Time” differences between London and Oxford were 5 minutes, between London and Leeds 6 minutes.
In England, during the 1840s, railroads were being built and cities connected. Railroads needed a set time across the country and so they set and followed “Railroad Time”. Based on Greenwich Mean Time. It was introduced throughout the country. It was not always observed as a standard. Many towns posted a different local time and railroad time. Railroad time and a single time zone were not codified until 1880 – however there was widespread adoption (around 90% of the country) before the laws were passed.
In the United States time zones were also driven by the railroads. Multiple crashes, starting in New England, were caused by different trains keeping different times. Finally in 1883 the United States set up 5 time zones. Those original time zones are used today, albeit with some major modifications.
Daylight Savings Time
Daylight Savings Time (DST) is the change of the official time by 1 hour. This is used in the upper and lower mid-latitudes to adjust for the changes in the solar day during the summer.
It was first adopted in Ontario Canada in 1908. The first it was used country-wide was in Germany and Austria during World War I. It was implemented to reduce the need for coal, longer daylight meant less need to generate electricity for lighting. As the war spread, other countries adopted it across Europe. The United States adopted it in 1918 – as we entered World War I.
Between the two World Wars DST was dropped by most countries. It was kept in Britain, Ireland, France, the United States, and Canada. But it was reintroduced and adopted by many countries during World War II.
Since the end of World War II changes have occurred often. Some areas changed Time Zone areas and the need for DST. Other areas simply stopped using DST. For example, Arizona does not change the clocks for Daylight Savings Time. Arizona stays on Mountain Standard Time while the states around it change. In the winter Arizona and New Mexico use the same time, in the summer, Arizona and California use the same time.
Uniform National Time
Several countries have ultimately moved off time zones for national integration. China and India are both very large countries and yet both have migrated to a single time zone for the entire country. Russia has merged time zones to reduce the number they observe from 11 to 9, but 2014 the regional differences changed.
Different locations will still set new time zones and offsets from GMT, and the standard set time has been set.
If you are interested, more about how digital devices keep time below.
How Clocks Were Set
Before computers, a nation’s official time was set by observatories. The observatories could set the offset from GMT and then share it with officials. In the United States times were then sent (often by telegraph) to federal buildings and town clocks. The clock towers would ring out the times and people could set their watches.
Later short wave broadcasts run by governments would continually count the time every minute and broadcast it. US government still runs a short-wave broadcast of the time. This time was also delivered to individuals by way of a telephone number which would give the famous “at the tone the time will be…”. Where I grew up in Southern California, the number was 853-1212. If you needed to set clocks, you called this number. Since my dad and I moved a LOT, I had to set a lot of clocks. You also had to reset them after a power outage, or earthquake or if you kicked the plug out accidentally.
Interestingly in doing some background about this, I learned that Oven Clocks did keep the best time because of the current frequency.
More Precise Time
Computers heralded the need for a shared exact time. At Xerox in the 1980s, one of the first distributed network systems before the world wide web, if the computer times were off by tenths of a second then the machines could not communicate. Therefore, each clock had to be set to a correct time. To do so Xerox used a US Time Service on the ARPA net. This first internet usage on ARPA between UCLA, Stanford, UC Santa Barbara, and University of Utah. This different sites had to coordinate to set a common method of setting time to a standard.
Now all computers use an internal UTC or Universal Time Zone (sometimes called Coordinated Universal Time). It is based on Greenwich mean time. Once a system comes up it contacts the Time Server for that network or computer provider. This time is coordinated as the number of seconds from a set period. Unix defines time as the number of seconds from Midnight, January 1, 1970 and is used for Mac OS, iOS, Android OS and Linux. Microsoft Time Server uses seconds from January 1, 1601. For people these calculations are difficult. For computers, these are simply and easy rules. When a new system comes online one of the first things it will do is broadcast a request for time. The system will continue to request time multiple times a minute to ensure it does not deviate.
For an excellent discussion of computer time access this LINK to company Next It.
How is Time First Set and Shared?
All of you reading have some computer, pad tablet or phone. And even more people around the world have cell phones. These cell phones, like computers, have simple calculations based on local time zone and time zone rules. The UTC is set through the same series of broadcast requests discussed above. Then the cell phone will check the time and correct for the time zone set and any daylight savings conditions.
When cell phones added location services, they started reacting to changing time zones AND you can communicate with the local network.
That is why when you land and turn on your phone, it takes a few minutes to get the right time information on your cell phone. As you turn it on it has to ask for the time. Since the time is different than it expects, it checks the geographic location you are at and modifies its internal rules for the new location.
You might have seen a manifestation of this yourself. Many people have wifi only iPads, Kindles or Tablets. When you travel to a new time zone and boot up, the screen will show the incorrect time. It will only update the time when it connects to the network. The steps would be:
The device tries to join the network. It is rejected because the time differential is too great.
The device sends out a broadcast for UTC and location services.
The device gets back the current UTC and its current location.
The device applies the time rules for the new location to the Universal Time it was given.
The device attempts to join the wifi network again. This time with the coordinated time and gets connected.
Side Note: Telling Time
More and more appliances, personal devices, computer assistants, cars, and more display time, can be uniformly shown numerically. This has led to a situation where many children and younger people cannot tell time via a traditional clock face – one with pointers that lead to approximate times.
Places that depended on precision like airports or scales used to be where you looked at time in minutes or weight in ounces were the places you found digital displays. When you asked people the timed it was usually relayed in increments like “about 15 to 2” or “2:30”. Now asking for the time will give an answer like “1:45” or on European clocks “14:16”.
Is the more precise time better or worse? For most of us traditionalist (read old) it is annoying and disconcerting at first. But we quickly accept it from others, and then usually have transitioned as most of our equipment becomes able to set itself.