Global time zone patterns reveal political and technical complexities

An analysis of global time zone structures reveals that offsets are often political decisions rather than strictly astronomical ones. Data from the IANA database covering 162 cities, countries, and regions shows that while many locations follow whole-hour offsets from UTC, several use half-hour or quarter-hour increments. Notable examples include Kathmandu, Nepal, which maintains a UTC+5:45 offset, and regions in India, Iran, and Afghanistan that utilize half-hour offsets.

Regarding daylight saving time, the data indicates a near-even split globally. Approximately 54% of the tracked locations shift their clocks seasonally, while 46% maintain a fixed offset year-round. Major regions such as East Asia, the Gulf, most of Africa, and India do not observe daylight saving time.

Technical implementations of time in software, such as PostgreSQL, must account for these complexities, including how the system handles timestamps with and without time zone awareness to ensure accuracy across different regional settings.