Tokyo is always 2 hours ahead of Bangkok. When it's 9:00 AM in Bangkok, it's 11:00 AM in Tokyo. Neither city observes DST, so this difference is constant year-round.
Tokyo uses JST (UTC+9) while Bangkok uses ICT (UTC+7).
Morning Bangkok works well! 9:00 AM - 4:00 PM Bangkok corresponds to 11:00 AM - 6:00 PM Tokyo. Good overlap for business hours.
Bangkok and Tokyo are popular tourist and business destinations. Thai Airways, ANA, and JAL operate frequent 6-hour flights on this busy route.