Saed News: A passenger plane took off this week in the early hours of 2025 from Hong Kong Airport's runway and landed at the last moments of 2024. This rare event only happens during the first hours of the New Year.
According to Saed News' social service, Cathay Pacific flight CX880 departed from Hong Kong International Airport at 12:21 AM local time on January 1, 2025. After approximately 12 hours of flight, it landed in Los Angeles at 8:33 PM local time on December 31, 2024.
Euronews wrote: The structure of spacetime remains unchanged, and the plane did not land before its flight; this event simply occurred due to time zone divisions and crossing the International Date Line (IDL).
The "International Date Line," a nearly vertical line, passes through the 180th meridian in the Pacific Ocean. When ships and planes cross it from west to east, they go back one calendar day.
A surprise called "Concorde"
However, to observe this effect, it’s not always necessary to cross the "International Date Line."
Previously, during the transition from 1999 to 2000, Air France gave its passengers the opportunity to "celebrate" the start of the new millennium "twice."
The passengers left Charles de Gaulle Airport in Paris at 1 AM local time on January 1, 2000, aboard a Concorde aircraft. They landed at John F. Kennedy Airport in New York at 11 PM local time on December 31, 1999. With this, they celebrated the millennium in both Paris and New York.
Since the Concorde flew at supersonic speeds, it was able to move fast enough to stay ahead of the Earth's rotation relative to local time.
Although the "International Date Line" is widely agreed upon by countries, it has no legal international status, and nations are free to choose their historical calendars.
The 180th meridian of the Earth passes through several lands, including the far east of Russia and some Fiji Islands. However, its passage through these countries did not impact their calendar days.
This again reminds us that many aspects of time zones and calendars are human-made, primarily designed to facilitate life, such as planning travel and standardizing communication worldwide.
Even the 24-hour day schedule is not fixed or definitive, as the Earth's rotation speed can be influenced by the moon and other celestial bodies. As a result, days can sometimes be slightly longer or shorter than 24 hours—though only by a few microseconds.
For example, between 1972 and 2020, the average day shortened by about 3 milliseconds (each millisecond equals one-thousandth of a second).
However, in the past four years, days have become slightly longer again, and no one knows exactly why.
