At several points around the world, three time zones meet.
A tripoint is any point on a map when three borders meet. National tripoints are fairly common, especially in Europe, Asia, Africa, and South America, and state / territorial / provincial tripoints are abundant as well.
Also common are land borders where a step over the line involves a shift in time zone. If you time it right, you can celebrate the New Year twice in a row, first on one side of the border and then stepping over that border to celebrate it all over again.
Put these two common border types together and you get something quite a bit rarer: a time zone tripoint. These points represent the intersection of three different time zones. You could literally walk in a circle and jump backwards and forwards in measured time.
The image above is of the Treriksrøysa, the cairn that signals the tripoint border between Russia, Finland, and Norway. Norway’s northern coastline curves quite far to the east, but the whole country stays in Central European Time (the same time zone used from Spain in the west to Poland and Norway in the east). Finland is the westernmost extremity of Eastern European Time (a time zone it shares with the Ukraine, Greece, and more). The western extremity of contiguous Russia – not counting the Kaliningrad Oblast, which I may write about another time, but including Saint Petersburg and Moscow – sits in Moscow Time. This tripoint, therefore, is a place where three time zones meet.
That’s the only time zone tripoint in Europe, but other continents have their own. The border between Laos, Myanmar (Burma), and China is one; Tajikistan, Kyrgyzstan, and China is another; China, North Korea, and Russia is yet another. Actually, a lot of the time zone tripoints are a result of China’s stubborn “one time zone for the whole country” policy – not counting Xinjiang’s extra time zone, of course.
The only time zone tripoint I could find in North America is the point where Alaska, the Yukon Territory, and British Columbia meet, but that point is unnamed and uncelebrated except by American climbing clubs with an eye to unusual records (see the last link below).
Australia holds the dubious record of having three time zone tripoints within the same country. Because the continent country stretches across so many time zones, and because each state or territory can decide for themselves how and whether to administer daylight savings time, you can traverse three time zones at any one of the following: Cameron Corner, Poeppel Corner, and Surveyor Generals Corner. It’s a good destination if you’re having a New Years Eve party and you want the good times to keep rolling on and on.
[Thanks to Alistair S.]