What exactly is the National Time Service Center, which has been relentlessly attacked by the United States?

What time is it when you're reading this article?

Readers in the front row might say it's 23:59.

But have you ever wondered, what makes you think it's 23:59 now? The time you see countless times a day in the top right corner of your phone, the bottom left corner of your screen, or on your watch, where does it actually come from?

Many people might instinctively think that the time is provided by the mobile phone operator or simply calculated by the phone itself.

However, on some social platforms, there are so - called ticket - grabbing tools and strategies claiming that your phone time is inaccurate and suggesting you open certain apps and so on.

So, the question is, where can we get the accurate time?

To summarize briefly, the unified and precise Beijing Time used by billions of people in China doesn't originate from Beijing. Its sole source is the National Time Service Center in Xi'an, Shaanxi Province.

Surprisingly, this seemingly harmless time management institution has been under continuous cyber - attacks from the United States for nearly two years.

They not only launched high - intensity cyber - attacks on multiple internal network systems of the National Time Service Center but also attempted to horizontally penetrate into the high - precision ground - based time service system and pre - set the ability to paralyze and damage it.

This makes people wonder. Why do the Americans go to so much trouble to attack our time management institution? Are they afraid we'll be late for work?

After some research, I found that unified and precise time is the fundamental infrastructure of the entire society. Controlling it is like holding the pulse of the whole society. Taking this opportunity, let's briefly talk about what Beijing Time is all about.

As we all know, a day is the time it takes for the Earth to rotate once.

Therefore, our perception of time is basically based on Universal Time. If we divide a day into 86,400 equal parts, each part is what we call a second.

Gradually, people found that the Earth's rotation seems to vary; sometimes it takes longer and sometimes shorter.

This is because of factors such as tidal phenomena and the movement of the Earth's core, which cause the Earth's rotation speed to constantly change.

Generally speaking, each day on Earth is getting longer. However, in some geological periods, there are also short - term accelerations. For example, in the past 20,000 years, each day has shortened by about 0.6 milliseconds.

Of course, there are also some special factors that can make the Earth rotate faster. For instance, the 8.9 - magnitude earthquake in Japan in 2011 directly accelerated the Earth's rotation by 1.8 microseconds.

On June 29, 2022, the Earth had its shortest day on record

To be honest, these small changes in time don't really matter to you and me. Some things will still take as long as they need to.

Later, scientists found that compared with the instability of the Earth's single - rotation, the combination of the Earth and the Sun's movements is more regular.

So in 1956, the definition of a second was changed to 3/31556925.9747 of the time it takes for the Earth to revolve around the Sun once.

However, this level of time accuracy is still not sufficient for some high - tech fields such as aerospace and satellite navigation.

For satellite positioning, each satellite continuously emits radio signals containing position and time information, with an accuracy of up to one - meter and one - billionth of a second. Even an error of 0.1 seconds, when multiplied by the speed of light, can lead to a huge deviation in satellite positioning.

Thus, International Atomic Time emerged.

Since the Earth, a large celestial body, has an unstable time - keeping ability, does a smaller object have better accuracy?

Surprisingly, it does.

For example, the current definition of a second is the time duration equal to 9,192,631,770 times the period of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium - 133 atom...

Based on this, high - precision atomic clocks using cesium elements were developed, and January 1, 1958, 00:00:00 was set as the starting point for atomic timekeeping.

Based on Universal Time and Atomic Time, we ordinary people use a new standard called Coordinated Universal Time (UTC).

Normally, it uses atomic time to ensure accuracy. However, when the difference between atomic time and universal time reaches 0.9 seconds, one second is added artificially, which is what we often hear about as a leap second.

Currently, the international community plans to stop introducing leap seconds no later than 2035.

The National Time Service Center mainly stores atomic clocks and related equipment to accurately determine time. Moreover, it has to send this accurate time to everyone.

Currently, the National Time Service Center mainly uses two types of time service methods: ground - based time service and space - based time service.

As the name suggests, ground - based time service involves sending time signals through ground facilities, like a network of "standard clock" broadcasting stations across the land.

For example, short - wave radio stations can be used to send radio waves. These signals are transmitted through sky waves and ground waves, and can basically cover the entire country with millisecond - level accuracy.

At the same time, long - wave radio stations can be used to cover the offshore areas of the country with microsecond - level accuracy.

Of course, if you have a radio - controlled clock or watch, you can also use the low - frequency time - code time service of the National Time Service Center. These clocks and watches can receive these signals and automatically adjust the time, with an accuracy of no more than one second of error in 300,000 years.

There are also other ground - based time service methods such as telephone, television, and network time service.

Currently, the most popular method is space - based time service, that is, satellite time service.

All kinds of navigation maps rely on the GNSS (Global Navigation Satellite System). Systems like the US GPS, China's Beidou (BDS), and Europe's Galileo all belong to the GNSS.

In addition to positioning and navigation, the GNSS also undertakes the function of time service.

Each GNSS satellite is equipped with an atomic clock, which means the satellite signals it sends contain accurate time data.

The ground receiver receives signals from at least four satellites, calculates the precise time it takes for the signals to travel from the satellites to the receiver, and then, combined with the satellite's position information, can not only determine its own position but also synchronize its own time with the standard time on the satellites, thus achieving high - precision time service.

Don't think that such a complex time - service system is just for people to know the accurate time for work every day.

In fact, this level of time accuracy is mainly for the service of fields such as aerospace, power, finance, communication, transportation, and national defense and military.

Take a common example in the financial field. As we all know, financial exchanges follow the principle of "price priority, time priority". If two people offer the same price, the one who places the order earlier will get the deal.

If I, Jiangjiang, want to buy a certain stock at exactly 10 o'clock, and my system time is accurate, I can buy it right at 10 o'clock.

Xiaohebpang also wants to buy the same stock at the same time. However, his time is inaccurate. Although he places the order at his 10 o'clock, the order actually reaches the exchange at 10:01.

As a result, I succeed in buying the stock, while Xiaohebpang fails.

But according to the timestamps in their respective systems, it seems that Xiaohebpang placed the order earlier, which is quite confusing.

If a company can use technology to affect the exchange's system time, it could take advantage of this loophole to make a fortune.

That's why the EU and the US have relevant requirements. For example, trading venues and investment companies in the EU must synchronize their system time with the world standard time, with an accuracy requirement of within 100 microseconds.

Similarly, the US Financial Industry Regulatory Authority requires synchronization with the time of the National Institute of Standards and Technology (NIST), with an accuracy requirement at the sub - second level.

This makes me think of the story in the movie *Bad Genius* about using time differences.

If such things happen in some military operations that require precise time coordination, it can be used to disrupt the enemy's command and communication systems, create chaos, and gain the initiative on the battlefield.

This is probably the real - world power of "controlling time".

That's why China attaches great importance to protecting the National Time Service Center. In the last century, the National Time Service Center was a classified department with the code 326. Even the atomic clocks and a series of equipment and departments were located underground with the goal of withstanding nuclear attacks.

After this explanation, do you think that "time", something we use every day but rarely think about, suddenly becomes more concrete and even crucial?

It's like air and water. We don't notice its existence in normal times, but once there's a problem, our entire social system may suffocate.

Fortunately, in this invisible "time war", we're not defenseless.

When the enemy launches an attack in the virtual world, we also have our own "time - space management agency". They guard not only the signals accurate to nanoseconds but also the pulse of our entire modern society.

Source of images and materials:

CCTV News: National security agencies cracked a major cyber - attack case by the US National Security Agency

*Approaching Science*, October 15, 2015: Scientific Heavyweights - The National Time Service Center

Science and Technology Daily: Why is the Earth's rotation also "in a hurry"?

Zhihu: What would happen if the National Time Service Center suffered a fatal damage?

EEWorld: In - depth Reveal: What Exactly is