The most difficult time zones riddles

Time zones range from UTC-12 to UTC+14. UTC+14 stretches as far as 30° east of the 180° longitude line and creates a large fold in the International Date Line. In Kiribati (UTC+14), the local time is the same as in Hawaiʻi (UTC−10:00), but the date is one day ahead. It is also 26 hours ahead of Baker Island (UTC−12:00).

Geographically, China covers five time zones (Zhongyuan, Longshu, Tibet, Kunlun and Changbai Time Zones). However, the standard times used in Chinese Mainland, Hong Kong, Macau, and Taiwan Province are the same, for they are all in the same time zone (UTC+8), 8 hours ahead of the Universal Time Coordinated.

India is one of the few countries that use single time zone with a 30-minute increment from UTC. The country's east–west distance covers 28 degrees of longitude, resulting in two hours difference in astronomical time. Since authorities decided to have one time zone for the whole country, they had to adjust it precisely.