Tokyo is UTC+9 (GMT+9, no DST). Mumbai is UTC+5:30 (GMT+5:30, no DST). Mumbai is currently 3 hours behind Tokyo.
Best times to meet (Tokyo local time): 12:00 PM — 9:00 AM in Mumbai; 1:00 PM — 10:00 AM in Mumbai; 2:00 PM — 11:00 AM in Mumbai; 3:00 PM — 12:00 PM in Mumbai; 4:00 PM — 1:00 PM in Mumbai.
Times shown in Tokyo local time → Mumbai local time. Based on business hours 09:00–17:00.
Tokyo observes Japan Standard Time (JST, UTC+9) year-round. Japan abolished Daylight Saving Time in 1951, after experimenting with it during the post-war US occupation (1948–1951), and has not reinstated it since. The fixed UTC+9 offset means that Tokyo's sunrise and sunset times shift significantly across seasons — the sun rises before 04:30 in late June and after 06:50 in late December — but the clock never moves. Japan Standard Time is shared by the entire country, which spans only about 30° of longitude, making a single national timezone practical.
Tokyo is the world's most populous metropolitan area and a global financial powerhouse. The Tokyo Stock Exchange (TSE) opens at 09:00 JST and closes at 15:30 JST with a lunch break from 11:30 to 12:30 — one of the few major exchanges still observing a midday break. Tokyo's fixed UTC+9 means the trading day never shifts relative to the rest of the world's schedules: TSE always closes at 06:30 UTC, just as European morning trading begins. The lack of DST simplifies scheduling with Tokyo; you never need to check "is Japan currently on DST?" — it is always UTC+9.
Tokyo is 9 hours ahead of London (GMT), 14 hours ahead of New York (EST), and 17 hours ahead of Los Angeles (PST). This puts Tokyo so far ahead of the Americas that a live daytime meeting covering both is virtually impossible during normal business hours for either side. It is 1 hour ahead of Beijing and Seoul, and exactly the same offset as South Korea (KST) in winter. The JST zone also covers South Korea's Jeju island in practice, though Korea officially uses KST (also UTC+9).
Mumbai observes India Standard Time (IST, UTC+5:30) year-round. India uses a single timezone for the entire country despite spanning about 30° of longitude — a political decision made at independence in 1947 to promote national unity. The unusual half-hour offset (UTC+5:30, rather than UTC+5 or UTC+6) was chosen to split the difference between the two natural candidates. India does not observe Daylight Saving Time, making IST one of the most stable and predictable offsets in Asia. The fixed UTC+5:30 is also used by Sri Lanka (identical offset, different name).
Mumbai is India's commercial and financial capital, home to the Bombay Stock Exchange (BSE) and the National Stock Exchange (NSE), both of which open at 09:15 IST and close at 15:30 IST. The half-hour offset creates frequent rounding issues in scheduling: an hour that is "clean" in London (10:00 GMT) corresponds to 15:30 IST — precisely the BSE closing bell. Mumbai is 5.5 hours ahead of London (GMT), 10.5 hours ahead of New York (EST), and 3.5 hours behind Tokyo (JST). The lack of whole-hour alignment means that India features prominently in scheduling challenges for global companies.
India's large IT and business process outsourcing (BPO) industry has adapted to the half-hour offset by creating shift structures that overlap with US time zones: a Mumbai engineer working 14:00–23:00 IST covers New York's 08:30–17:30 EST window almost exactly. India's 1.4 billion people make it one of the world's most important consumer and producer economies, and the IST timezone has become extremely well-known among global project managers. The country's time is sometimes called "Indian Stretchable Time" in a cultural joke about flexible punctuality — though the timezone itself is as fixed as any.
Mumbai is currently 3 hours behind Tokyo.
When it is 12:00 noon in Tokyo, it is 09:00 in Mumbai (based on current offsets — verify during DST transitions).
Tokyo does not observe DST — GMT+9 is used year-round. Mumbai does not observe DST — GMT+5:30 is used year-round.