If you’ve ever tried to keep track of time without a watch or clock, you’ll realise just how difficult it can be. Over a few hours, you may get to within half an hour of the right time, but precise time is very difficult to measure without some form of chronological device.

Before the use of clocks, keeping time was incredibly difficult, and even losing track of days of the years became easy to do unless you kept as daily tally. But the development of accurate timepieces took a long time, but several key steps in chronology evolved enabling closer and closer time measurements.

Today, with the benefit of atomic clocks, NTP servers and GPS clock systems, time can be monitored to within a billionth of a second (nanosecond), but this sort of accuracy has taken mankind thousands of years to accomplish.

Stonehenge--ancient timekeeping

Stonehenge

With no appointments to keep or a need to arrive at work on time, prehistoric man had little need for knowing the time of day. But when agriculture started, knowing when to plant crops became essential for survival. The first chronological devices such as Stonehenge are believed to have been built for such a purpose.

Identifying the longest and shortest days of the year (solstices) enabled early farmers to calculate when to plant their crops, and probably provided a lot of spiritual significance to such events.

Sundials

The provided the first attempts at keeping track of time throughout the day. Early man realised the sun moved across the sky at regular paths so they used it as a method of chronology. Sundials came in all sorts of guises, from obelisks that cast huge shadows to small ornamental sundials.

Mechanical Clock

The first true attempt at using mechanical clocks appeared in the thirteenth century. These used escapement mechanisms and weights to keep time, but the accuracy of these early clocks meant they’d lose over an hour a day.

Pendulum Clock

Clocks first became reliable and accurate when pendulums began appearing in the seventeenth century. While they would still drift, the swinging weight of pendulums meant that these clocks could keep track of first minutes, and then the seconds as engineering developed.

Electronic Clocks

Electronic clocks using quartz or other minerals enabled accuracy to parts of a second and enabled scaling down of accurate clocks to wristwatch size. While mechanical watches existed, they would drift too much and required constant winding. With electronic clocks, for the first time, true hassle free accuracy was achieved.

Atomic Clocks

Keeping time to thousands, millions and even billion parts of a second came when the first atomic clocks arrived in the 1950’s. Atomic clocks were even more accurate than the rotation of the Earth so Leap Seconds needed developing to make sure the global time based on atomic clocks, Coordinated Universal Time (UTC) matched the path of the sun across the sky.

The argument about the use of the Leap Second continues to rumble on with astronomers again calling for the abolition of this chronological ‘fudge.’

Galleon's NTS 6001 GPS

The Leap Second is added to Coordinated Universal Time to ensure the global time, coincides with the movement of the Earth. The problems occur because modern atomic clocks are far more precise than the rotation of the planet, which varies minutely in the length of a day, and is gradually slowing down, albeit minutely.

Because of the differences in time of the Earth’s spin and the true time told by atomic clocks, occasional seconds need adding to the global timescale UTC—Leap Seconds. However, for astronomers, leap seconds are a nuisance as they need to keep track of both the Earth’s spin—astronomical time—to keep their telescopes fixed on studied objects, and UTC, which they need as atomic clock source to work out the true astronomical time.

Next year, however, a group of astronomical scientists and engineers, plan to draw attention to the forced nature of Leap Seconds at the World Radiocommunication Conference. They say that as the drift caused by not including leap seconds would take such a long time—probably over a millennia, to have any visible effect on the day, with noon gradually shifting to afternoon, there is little need for Leap Seconds.

Whether Leap Seconds remain or not, getting an accurate source of UTC time is essential for many modern technologies. With a global economy and so much trade conducted online, over continents, ensuring a single time source prevents the problems different time-zones could cause.

Making sure everybody’s clock reads the same time is also important and with many technologies millisecond accuracy to UTC is vital—such as air traffic control and international stock markets.

NTP time servers such as Galleon’s NTS 6001 GPS, which can provide millisecond accuracy using the highly precise and secure GPS signal, enable technologies and computer networks to function in perfect synchronicity to UTC, securely and without error.

June 21 marks the summer solstice for 2011. The summer solstice is when the Earth’s axis is most inclined to the sun, providing the most amount of sunshine for any day of the year. Often known as Midsummer’s day, marking the exact middle of the summer, periods of daylight get shorter following the solstice.

For the ancients, the summer solstice was an important event. Knowing when the shortest and longest days of the year were important to enable early agricultural civilisations to establish when to plant and harvest crops.

Indeed, the ancient monument of Stonehenge, in Salisbury, Great Britain, is thought to have been erected to calculate such events, and is still a major tourist attraction during the solstice when people travel from all over the country to celebrate the event at the ancient site.

Stonehenge is, therefore, one of the oldest forms of timekeeping on Earth, dating back to 3100BC.While nobody knows exactly how the monument was built, the giant stones were thought to have been transported from miles away—a mammoth task considering the wheel hadn’t even been invented back then.

The building of Stonehenge shows that timekeeping was as important to the ancients as it is to us today. The need for acknowledging when the solstice occurred is perhaps the earliest example of synchronisation.

Stonehenge probably used the setting and rising of the sun to tell the time. Sundials also used the sun to tell the time way before the invention of clocks, but we have come a long way from using such primitive methods in our timekeeping now.

Mechanical clocks came first, and then electronic clocks which were many times more accurate; however, when atomic clocks were developed in the 1950’s, timekeeping became so accurate that even the Earth’s rotation couldn’t keep up and an entirely new timescale, UTC (Coordinated Universal Time) was developed that accounted for discrepancies in the Earth’s spin by having leap seconds added.

Today, if you wish to synchronise to an atomic clock, you need to hook up to a NTP server which will receive an UTC time source from GPS or a radio signal and allow you to synchronise computer networks to maintain 100% accuracy and reliability.

Stonehenge--Ancient timekeeping

Development in clock accuracy seems to increase exponentially. From the early mechanical clocks, there were only accurate to about half an hour a day, to electronic clocks developed at the turn of the century that only drifted by a second. By the 1950’s, atomic clocks were developed that became accurate to thousandths of a second and year on year they have becoming ever more precise.

Currently, the most accurate atomic clock in existence, developed by NIST (National Institute for Standards and Time) loses a second every 3.7 billion years; however, using new calculations researchers suggest they can now come up with a calculation that could lead to an atomic clock that would be so accurate it would lose a second only every 37 billion years (three times longer than the universe has been in existence).

This would make the atomic clock accurate to a quintillionth of a second (1,000,000,000,000,000,000th of a second or 1x 10¹⁸). The new calculations that could aid the development of this sort of precision has been developed by studying the effects of temperature on the miniscule atoms and electrons that are used to keep the atomic clocks ‘ticking’. By working out the effects of variables like temperature, the researchers claim to be able to improve the accuracy of atomic clock systems; however, what possible uses does this accuracy have?

Atomic clock accuracy is becoming ever relevant in our high technology world. Not only do technologies like GPS and broadband data streams rely on precise atomic clock timing but studying physics and quantum mechanics requires high levels of accuracy enabling scientists to understand the origins of the universe.

To utilise an atomic clock time source, for precise technologies or computer network synchronisation, the simplest solution is to use a network time server; these devices receive a time stamp direct from an atomic clock source, such as GPS or radio signals broadcast by the likes of NIST or NPL (National Physical Laboratory).

These time servers use NTP (Network Time Protocol) to distribute the time around a network and ensure there is no drift, making it possible for your computer network to be kept accurate to within milliseconds of an atomic clock source.

Network Time Server

When you tell somebody you’ll be an hour, ten minutes or a day, most people have a good idea how long they need to wait; however, not everybody has the same perception of time, and in fact, some people have no perception of time at all!

Scientists studying a newly discovered Amazonian tribe have found that they have no abstract concept of time, according to news reports.

The Amondawa, first contacted by the outside world in 1986, while recognising events occurring in time, do not recognise time as a separate concept, lacking the linguistic structures relating to time and space.

Not only do the Amondawa have no linguistic ability to describe time, but concepts like working throughout the night, would not be understood as time has no meaning to their lives.

While most of us in the western world tend to live by the clock, we all in fact have continuous different perceptions of time. Ever noticed how time flies when you’re having fun, or goes very slowly during times of boredom? Our time perceptions can vary greatly depending on the activities that we are undertaking.

Fighter pilots, Formula One drivers and other sportsmen often talk of “being in the zone” where time slows down. This is due to the intense concentration they are putting into their endeavours, slowing down their perceptions.

Regardless of out differing time perceptions, time itself can alter as Einstein’s Special Theory of Relativity demonstrated. Einstein suggested that gravity and intense speeds will alter time, with large planetary masses warping space-time slowing it down, while at very high speeds (close to the speed of light) space travellers could partake a journey that to observers would seem several thousands of years, but be just seconds to those travelling at such speeds.

And if Einstein’s theories seem far-fetched, it has been tested using ultra-precise atomic clocks. Atomic clocks on aeroplanes travelling around the Earth, or placed farther away from the Earth’s orbit, have minute differences to those remaining at sea-level or stationary on Earth.

Atomic clocks are useful tools for modern technologies and help to ensure that the global timescale, Universal Coordinated Time (UTC), is kept as accurate and true as possible. And you don’t need to own your own tomake sure your computer network is kept true to UTC and is hooked up to an atomic clock. NTP time servers enable all sorts of technologies to receive an atomic clock signal and keep as accurate as possible. You can even buy atomic clock wall clocks that can provide you the precise time no matter how much the day is “dragging” or “flying”.

Atomic Wall clocks from Galleon Systems

The launch date for the first Galileo satellites, the European version of the Global Positioning System (GPS), has been scheduled for mid October, say the European Space Agency (ESA).

Two Galileo in-orbit validation (IOV) satellites will be launched using a modified Russian Soyus rocket this October, marking a milestone in the Galileo project’s development.

Originally scheduled for August, the delayed October launch will lift off from ESA’s spaceport in French Guiana, South America, using the latest version of the Soyuz rocket—the world’s most reliable and most used rocket in history(Soyus was the rocket that propelled both Sputnik—the first orbital satellite—and Yuri Gargarin—the first man in orbit—into space).

Galileo, a joint European initiative, is set to rival the American controlled GPS, which is controlled by the United States military. With so many technologies reliant on satellite navigation and timing signals, Europe needs its own system in case the USA decides to switch off their civilian signal during times of emergency (war and terrorist attacks such as 9/11) leaving many technologies without the crucial GPS signal.

Currently GPS not only controls the words transportation syste3ms with shipping, airliners and motorists increasingly becoming reliant on it, but GPS also provides timing signals to technologies such as NTP servers, ensuring accurate and precise time.

And the Galileo system will be good for current GPS users too, as it will be interoperable and, therefore, will increase accuracy of the 30-year-old GPS network, which is in need of upgrade.

Currently, a prototype Galileo satellite, GIOVE-B, is in orbit and has been functioning perfectly for the last three years. Onboard the satellite, as with all global navigation satellite system (GNSS) including GPS, is an atomic clock, which is used to transmit a timing signal that Earth-based navigation systems can use to triangulate accurate positioning (by using multiple satellite signals).

The atomic clock aboard GIOVE-B is currently the most accurate atomic clock in orbit, and with similar technology intended for all Galileo satellite, this is the reason why the European system will be more accurate than GPS.

These atomic clock systems are also used by NTP servers, to receive an accurate and precise form of time, which many technologies are dependent on to ensure synchronicity and accuracy, including most of the world’s computer networks.

Global time synchronisation may seem like a modern need, we do after all live in a global economy. With the internet, global financial markets and computer networks separated by oceans and continents—keeping everybody running in synchronisation is a crucial aspect of the  modern world.

Yet, a need for global synchronicity began a lot earlier than the computer age. International standardisation of weights and measures began after the French revolution when the decimal system was introduced and a platinum rod and weight representing the metre and the kilogram were installed in the Archives de la République in Paris.

Paris eventually became the central head of the International System of Units, which was fine for weights and measures, as representatives from different countries could visit the vaults to calibrate their own base measurements; however, when it came to standardising time, with the increased use of transatlantic travel following the steamer, and then the aeroplane, things became tricky.

Back then, the only clocks were mechanical and pendulum driven. Not only would the base clock that was situated in Paris drift on a daily basis, but any traveller from the other side of the world wanting to synchronise to it, would have to visit Paris, check the time on the vault’s clock, and then carry their own clock back across the Atlantic—inevitable arriving with a clock that had drifted perhaps several minutes by the time the clock arrived back.

With the invention of the electronic clock, the aeroplane and transatlantic telephones, things became easier; however, even electronic clocks can drift several seconds in a day so the situation wasn’t perfect.

These days, thanks to the invention of the atomic clock, the SI standard of time (UTC: Coordinated Universal Time) has so little drift even a 100,000 years wouldn’t see the clock lose a second. And synchronising to UTC couldn’t be simpler no matter where you are in the world—thanks to NTP (Network Time Protocol) and NTP servers.

Now using GPS signals or transmissions put out by organisations like NIST (National Institute for Standards and Time-WVBB broadcast) and NPL (National Physical Laboratory—MSF broadcast) and using NTP servers, ensuring you are synchronised to UTC is simple.

NTP servers like Galleon’s NTS 6001 GPS receive a atomic clock time signal and distributes it around a network keeping every device to within a few milliseconds of UTC.

Galleon's NTS 6001 GPS Time Server

The National Institute for Standards and Technology (NIST) is one of the world’s leading atomic clock laboratories, and is the leading American time authority. Part of a constellation of national physics laboratories, NIST help ensure the worlds atomic clock time standard UTC (Coordinated Universal Time) is kept accurate and is available for the American people to use as a time standard.

All sorts of technologies rely on UTC time. All the machines on a computer network are usually synchronised to source of UTC, while technologies such as ATM’s, closed-circuit television (CCTV) and alarm systems require a source of NIST time to prevent errors.

Part of what NIST does is to ensure that sources of UTC time are readily available for the technologies to utilise, and NIST offer several means of receiving their time standard.

The Internet

The internet is the easiest method of receiving NIST time and in most Windows based operating systems, the NIST time standard address is already included in the time and date settings, allowing easy synchronisation. If it isn’t, to synchronise to NIST you simply need to double click on the system clock (bottom right hand corner) and enter the NIST server name and address. A full list of NIST Internet servers, here:

The Internet, however, is not a particularly secure location to receive a source of NIST time. Any Internet time source will require and open port in the firewall (UDP port 123) for the time signal to get through. Obviously, any gap in a firewall can lead to security issues, so fortunately NIST provide another method of receiving their time.

NTP Time Servers

NIST, from their transmitter in Colorado, broadcasts a time signal that all of North America can receive. The signal, generated and kept true by NIST atomic clocks, is highly accurate, reliable and secure, received externally to the firewall by using a WWVB timeserver (WWVB is call sign for the NIST time signal).

Once received, the protocol NTP (Network Time Protocol) will use the NIST time code and distribute it around the network and will ensure each device keeps true to it, continually making adjustments to cope with drift.

WWVB NTP time servers are accurate, secure and reliable and a must-have for anybody serious about security and accuracy who wants to receive a source of NIST time.

Having suffered earthquakes, a catastrophic tsunami, and a nuclear accident, Japan has had a terrible start to the year. Now, weeks after these terrible incidents, Japan is recovering, rebuilding their damaged infrastructure and trying to contain the emergencies at their stricken nuclear power plants.

But to add insult t injury, many of the Japanese technologies that rely on an accurate atomic clock signals are starting to drift, leading to problems with synchronisation. Like in the UK, Japan’s National Institute of Information, Communications and Technology broadcast an atomic clock time standard by radio signal.

Japan has two signals, but many Japanese NTP servers rely on the signal broadcast from mount Otakadoya, which is located 16 kilometres from the stricken Daiichi power station in Fukushima, and falls within the 20 km exclusion zone imposed when the plant started leaking.

The consequence is that technicians have been unable to attend to the time signal. According to the National Institute of Information, Communications, and Technology, which usually transmits the 40-kilohertz signal, broadcasts ceased a day after the massive Tohoku earthquake struck the region on 11 March. Officials at the institute said they have no idea when service might resume.

Radio signals that broadcast time standards can be susceptible to problems of this nature. These signals often experience outages for repair and maintenance, and the signals can be prone to interference.

As more and more technologies, rely on atomic clock timing, including most computer networks, this susceptibility can cause a lot of apprehension amongst technology managers and network administrators.

Fortunately, a less vulnerable system of receiving time standards is available that is just as accurate and is based on atomic clock time—GPS.

The Global Positioning System, commonly used for satellite navigation, contains atomic clock time information used to calculate positioning. These time signals are available everywhere on the planet with a view of the sky, and as it is space-based, the GPS signal is not susceptible to outages and incidents such as in Fukushima.

As a manufacturer of NTP time servers, synchronizing computer networks and keeping them accurate to within a few milliseconds of international UTC time (Coordinated Universal Time), we often think we can keep pretty good track of time.

Time, however, is quit elusive and is not the fixed entity we often assume it is, indeed time, and the time told on Earth is not constant and is affected by all sorts of things.

Since Einstein’s famous equation, E=MC² it has been acknowledged that time is not constant, and that the only constant in the universe is the maximum velocity of light. Time, as Einstein discovered, is affected by gravity, making the time on Earth run slightly slower than time in deep space, likewise, on planetary bodies with a larger mass than Earth, time runs even slower.

Time slows down when you approach very fast speeds too. The property of time, known as time dilation, was discovered by Einstein and means that at close to the speed of light, time almost stands still (and makes interstellar travel a possibility for science fiction writers).

Generally, living on Earth, these differences in time are not felt, and indeed the slowing of time caused by Earth’s gravity is so minute, highly precise atomic clocks are required to measure it.

However, the time we use to govern our lives is also affected by other factors. Since humans first evolved, we have been used to a day lasting just over 24 hours.  However, the length of a day on Earth is not fixed, and has been changing for the last few billion years.

Each day on Earth differs from the previous to the next one. Often these differences are minute, but year on year, the changes add up as the affect of the moon’s gravity and tidal forces act as a brake on the Earth’s spin.

To cope with this, the global timescale UTC (Coordinated Universal Time) has to be adjusted to prevent the day from drifting out of sync (and we end up with noon at night and midnight during the day—although at the current slowing of the Earth, this would take many thousands of years).

The adjustment in our time is known as leap seconds which are added either once or twice a year to UTC. Anybody using a NTP time server (Network Time Protocol) to synchronise their computer network too, needn’t worry, however, as NTP servers will automatically account for these changes.