The International Date
Line has never been established by statute or treaty. Rather it has
been agreed to and utilized by nations involved in international
trade. It is the anti-meridian, 180° E or W of Greenwich. Although, In
general it follows that meridian, there are several significant
deviations. The first one (1867) is between Asia and North America in
the Bering Strait. Another (1892) put Samoa on the east side of the
Date Line and Tonga and Fiji on the west. The other major modification
(1995) moved the date line east to extend around, rather than through,
the territory of Kiribati. There have been other modifications, but
these the ones currently recognized.
In 1962 when the stamp was issued, the International
Date Line passed approximately 7.5° to the east of Fiji.