Rajini Vaidyanathan
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About Time: Indiana's changing clocks

Theoretically, the world should be divided into 24 equal time zones, in which each zone differs from the last by one hour. But as the years have passed, the world has turned into a much more complicated place.

Time zones are now much more irregular and sometimes seem positively eccentric, affected as they are by political, geographical and social changes in the real world.

Add to that arguments over daylight saving, and you have a subject that has been the cause of furious debate around the world.

The US state of Indiana has had a complicated history when it comes to time zones, stemming from the fact that it straddles Eastern and Central Time.

Rajini Vaidyanathan got up very early in the morning to find out more.