Did You Know?
The World's Computers Call China's Time Zone "Asia/Shanghai"
In 2025 the Port of Shanghai handled more than 55 million twenty-foot equivalent containers.
Work out what that means per unit of time and the number stops being abstract. Fifty-five million containers a year is about 150,000 a day, 6,300 an hour, or roughly 1.7 containers every second — continuously, day and night, weekends included, all year.
Shanghai has been the world's busiest container port every year since 2010. In 2024 it became the first port in history to pass 50 million TEU, finishing the year on 51.51 million. The 50-millionth container was lifted on the morning of 22 December 2024, wrapped in red, at the Yangshan Phase IV automated terminal.
Yangshan is worth its own sentence. It is a fully automated deep-water port built on reclaimed islands thirty kilometres offshore, connected to the mainland by bridge, and in 2025 it handled 28.71 million TEU by itself — more than half of Shanghai's total, and more than almost any other port on Earth handles in full.
The port is served by nearly 350 international shipping lines, connecting more than 700 ports in over 200 countries and regions. Shanghai Customs puts the average daily value of goods moving through at about 29.8 billion yuan — roughly US$4 billion a day, or 1.24 billion yuan every hour.
In 1994 the port handled one million containers for the first time. By 2025 it had multiplied that by fifty-five.
The clock: and here is the detail that makes this a Shanghai story rather than a Chinese one.
Every phone, server and operating system on Earth stores time zones using the same reference: the IANA time zone database, a set of files maintained collaboratively and used by essentially all modern software.
In that database, the time zone covering all of mainland China — the one officially called Beijing Time — is not called `Asia/Beijing`.
It is called `Asia/Shanghai`.
The database's convention is to name zones after the most populous city they contain, rather than the political capital, and Shanghai is the larger city. So the world's computers have spent decades quietly filing China's national time under a different name from the one China uses for it.
If you have ever set a server's clock, configured a database, or picked a time zone from a dropdown menu, you have used it.
And there is a second, better reason the name fits.
Beijing Time is built around the 120th meridian. Beijing itself sits at 116.4° east, which puts the capital roughly fourteen minutes ahead of its own sun. Kashgar, at the far western end of the same time zone, is out by around three hours.
Shanghai sits at 121.5° east.
Which means that out of the entire enormous span of Chinese territory running on Beijing Time — five geographic time zones' worth, from the Pacific coast to the borders of Central Asia — the major cities where the official clock and the actual sun genuinely agree lie near the east coast, and the capital is not one of them.
Solar noon in Shanghai arrives within a few minutes of twelve o'clock. The city is one of the most accurately timed places in this entire series.
The country's time is named after its capital. The world's software names it after Shanghai. And the sun, which was not consulted by either, quietly agrees with the software.
Sources
- Shanghai Municipality official statement (Record exceeding 55 million TEU in 2025, 16th consecutive year; Yangshan's 28.71 million TEU and 52.2% share)
- Seatrade Maritime and portshanghai.com (51.51 million TEU in 2024; fifty millionth container on 22 December 2024; ~350 lines, 700+ ports, 200+ countries)
- Chinese Government official site / Shanghai Customs (average 29.8 billion yuan ≈ 4 billion dollars per day; 1.24 billion yuan per hour; 1 million TEU for the first time in 1994; exceeding 40 million with Yangshan Phase IV in 2017)
- Maritime Executive (49 container berths, 176 cranes, 7.58 million m² of site)
- UNIS (Yangshan is located 30 km off the coast, on reclaimed islands)
- IANA time zone database, `Asia/Shanghai` entry and its naming rule (*theory.html*: zones are named after the most populous city); Wikipedia, *Time in China* and *Xinjiang Time*
- Longitude calculations: Shanghai 121.5°E, Beijing 116.4°E, UTC+8 meridian 120°E