How did you make your own 'atomic wristwatch' that uses atoms to keep track of time?

Atomic clocks are clocks that keep the most accurate time by applying the property that atoms and molecules absorb and emit radio waves and light of unique frequencies. Tom van Burke, a software developer living in Washington, USA, is the person who created the 'world's first atomic watch' that made it possible to carry such an atomic clock.

First Atomic Clock Wristwatch
http://leapsecond.com/pages/atomic-bill/

The exact time created by the atomic clock is transmitted as standard radio waves , which is the national standard time, and the International System of Units (SI) ' 1 second ' is also defined by the cesium atomic clock .

Atomic clocks are used for more than just measuring the length of time. It was measured by installing atomic clocks at two points where there is a difference in altitude, using the time lag due to gravity that ' time flows slowly in places with high gravity, and conversely flows fast in places with low gravity'. Experiments are also being conducted to measure the elevation difference between two points based on the time lag.

Interested in mathematics, physics, digital electronics, etc., Burke is a 'time enthusiast' who installs a clock at his home to measure accurate time at the government level or uses an atomic clock. He is a person who conducts experiments such as trying to observe the time lag due to gravity. One day, Mr. Burke thought, 'Is it possible to turn an atomic clock into a wristwatch?' And put it into practice.

Mr. Burke asked his brother-in-law, Mr. Bill, to realize an 'atomic wristwatch' by wearing a box-shaped cesium atomic clock ' 5071A ' on his arm with a nylon band. The picture below is Mr. Bill wearing a cesium atomic clock on his wrist.

The cesium atomic clock worn with two nylon bands is ...

It is possible to check the most accurate time on the LED display. In addition, since the battery is also included, it is possible to carry it while actually wearing it as a wristwatch. However, the battery lasts only 45 minutes and weighs about 30 kg, making it a difficult watch to move while wearing it unless you are very strong.