JST to UTC
Input
2026-01-31 09:00 JST
Output
2026-01-31 00:00 UTC
Timezone Converter (JST/UTC and IANA Time Zones)
Convert date and time instantly between JST, UTC, and IANA time zones.
Handle day rollovers, compare multiple zones, share with URL state, and copy results in one screen.
Fast JST↔UTC conversion
Clear rollover highlight (previous/next day)
Share and restore with URL state
What This Tool Can Do
- Bidirectional conversion between JST and UTC
- Date and time conversion using IANA zones worldwide
- Previous/next-day rollover badges
- Batch multi-line conversion with CSV/TSV copy
- World clock view for the same instant across zones
How to Use
- Select the source time zone and date/time.
- Choose one or more target time zones.
- Copy display or ISO format, then share as needed.
Common Conversion Examples
Day rollover (previous day)
Input
2026-01-01 00:30 JST
Output
2025-12-31 15:30 UTC (Previous day -1)
What Is a Time Zone?
UTC
Coordinated Universal Time. The global baseline for local times.
IANA Time Zone
A region-based identifier such as Asia/Tokyo that reflects local rules, including DST.
Abbreviations (JST/PST etc.)
Abbreviations can be ambiguous. IANA zone IDs are recommended.
Notes
- DST is applied automatically when you use IANA time zones.
- Results can vary slightly depending on the runtime time zone database version.
- On DST transition dates, some local times may not exist or may occur twice.
FAQ
How is DST handled?
If you specify an IANA time zone (for example, America/New_York), DST is applied automatically for that date/time. Results may depend on the runtime time zone database.
Can I see date rollovers?
Yes. If the source and target dates differ, the tool shows a rollover badge and the day difference.
Can I do bulk conversion?
Yes. You can paste multiple lines and convert each line independently, then copy the result as CSV/TSV. Errors in one line do not stop the others.
Is JST always UTC+9?
Japan Standard Time is currently operated as UTC+9.
Which format should I paste into meeting invites?
Use the display format for humans and ISO 8601 for system integration.