Why do India and China have single time zones despite their vast landmass?

US President Donald Trump has shown his interest in ending the Daylight Saving Time, which could add to complications in the United States functionality, which is divided in several time zones. Meanwhile, India and China, two of the world’s largest countries by landmass and population, operate under a single time zone — a decision driven by historical, political, and practical considerations. Historical Context and Rationale India’s single time zone, Indian Standard Time, was established during British colonial rule and has remained unchanged since independence. Multiple time zones better accommodate regional lifestyles, customs, and economic activities while ensuring local populations can operate efficiently within natural daylight hours. With Donald Trump vowing to end Daylight Saving Time, and as societal and economic needs evolve, the debate over introducing multiple time zones in countries like India and China could gain further momentum.