Japan operates on a single timezone year-round: Japan Standard Time (JST), set at UTC+9. There is no daylight saving time in Japan — clocks never change, and the country has not observed DST since 1952.
This makes Japan one of the world's most predictable timezones for international scheduling. All 47 prefectures — from Hokkaido in the north to Okinawa in the south — use JST without exception.
Key time differences from Tokyo: London (GMT) is 9 hours behind JST in winter, 8 hours behind during BST. New York (EST) is 14 hours behind JST. Los Angeles (PST) is 17 hours behind JST. Beijing and Singapore are 1 hour behind JST. Sydney (AEST) is 1 hour ahead in winter, on the same time during Australian DST. Dubai is 5 hours behind JST. Mumbai is 3.5 hours behind.
The Japan–US time difference is significant: Tokyo's business day (9 AM–6 PM JST) falls entirely within the previous calendar day for the US East Coast. A 9 AM Tokyo meeting is 8 PM EST the night before. This makes same-day overlap very limited — typically only the early morning hours in Japan align with any US business hours.