What is a proof that the international date line exists?

Answer 1

Throughout almost the past 2 centuries, thousands of cruise ships, cargo ships,

tankers, and a few intrepid solo adventurers have crossed the mid-Pacific, totaling

many thousands of passengers. On alerts from the ships' navigating officers that

long ago became a seafaring tradition, passengers are always notified when a

vessel is about to cross the International Date Line, and they typically flock to the

rails to look for it. Except on the darkest nights, or on the days when the sea is most

turbulent, crowds of people routinely see the line, black and straight and only a few

feet beneath the surface, as the ship glides silently across it and the ship's chronometers

trip in unison to the next or previous day, depending on their direction of travel.

So many sea travelers through a continuous period of almost 200 years have seen the

line, and have even raised a glass and toasted it with their fellow travelers at the

instant of the crossing, that its existence is now common knowledge on the sea, and

no shred of doubt remains in the mind of anyone who has personally traveled by sea,

or who knows anyone who has. In our day, the existence of the line has been confirmed

by thousands of witnesses, sound of body, mind, and sight, no less than that of the

ocean itself.

Answer 2

The International Date Line is an imaginary line that follows the 180° meridian on the Earth's surface, specifically designed to separate two consecutive calendar dates. It serves as the reference point for determining the change in dates as one travels across the line from east to west or vice versa. This shift is essential to maintain an accurate and coherent global calendar system.