There is no specific time zone at the South Pole.

There is no specific time zone at the South Pole.

The South Pole, on the other hand, is the southernmost point on the globe and is the point of intersection between the Earth's surface and its axis. Therefore, the two poles or points are located directly opposite each other. ... Due to the location of the North and South Poles, no specific time zone are observed.

Antarctica sits on every line of longitude, due to the South Pole being situated on the continent.
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TZ database.

Coordinates*	−7750+16636
Zone name*	Antarctica/McMurdo
Comment*	New Zealand time - McMurdo, South Pole
UTC offset standard time	+12

How is the Time determined at the Geographic Poles? As we know that human settlement are not possible on the geographic poles. Therefore, no specific time zone has been assigned for the geographic poles. The explorers and polar expeditions are free to choose whatever time zones are convenient for them.

twelve time zones

Antarctica has been crudely split between several world powers over the decades, and temporary inhabitants tend to operate under their respective time zones. However, this isn't always the case, as evidenced by the fact that while seven countries have claimed a stake on Antarctica, twelve time zones are observed.