JST to MDT Converter
Convert Japan Standard Time (JST) to Mountain Daylight Time (MDT) in one step. Because mDT is 15 hours behind JST, the math is a fixed 15 hours shift. Adjust the time or date and watch it update.
Daylight saving notes
In the United States and Canada, daylight saving time runs from the second Sunday in March to the first Sunday in November. That affects Mountain Daylight Time (MDT).
JST to MDT conversion chart
For example, a 9:00 AM JST meeting takes place at 6:00 PM MDT (−1 day). Concretely, when Tokyo (JST) and Denver (MDT) set up a call, mDT is 15 hours behind JST.
| JST time | MDT time |
|---|---|
| 12:00 AM | 9:00 AM−1 day |
| 1:00 AM | 10:00 AM−1 day |
| 2:00 AM | 11:00 AM−1 day |
| 3:00 AM | 12:00 PM−1 day |
| 4:00 AM | 1:00 PM−1 day |
| 5:00 AM | 2:00 PM−1 day |
| 6:00 AM | 3:00 PM−1 day |
| 7:00 AM | 4:00 PM−1 day |
| 8:00 AM | 5:00 PM−1 day |
| 9:00 AM | 6:00 PM−1 day |
| 10:00 AM | 7:00 PM−1 day |
| 11:00 AM | 8:00 PM−1 day |
| 12:00 PM | 9:00 PM−1 day |
| 1:00 PM | 10:00 PM−1 day |
| 2:00 PM | 11:00 PM−1 day |
| 3:00 PM | 12:00 AM |
| 4:00 PM | 1:00 AM |
| 5:00 PM | 2:00 AM |
| 6:00 PM | 3:00 AM |
| 7:00 PM | 4:00 AM |
| 8:00 PM | 5:00 AM |
| 9:00 PM | 6:00 AM |
| 10:00 PM | 7:00 AM |
| 11:00 PM | 8:00 AM |
This chart uses the fixed JST and MDT offsets; the live converter above follows current daylight saving.
Convert JST to MDT Time Zone
Below are the answers people search for most when converting Japan Standard Time (JST) to Mountain Daylight Time (MDT).
How does the JST to MDT converter work?
It takes three quick steps:
- Click the JST field on the left and pick the time you want to convert.
- The matching MDT time updates on the right automatically — there’s no button to press.
- Need a different day? Click the date field and the result follows, rolling over if it crosses midnight.
What is the time difference between JST and MDT?
MDT is 15 hours behind JST. In everyday terms, once you know the time on one side you just subtract 15 hours to get the other — so a call between Tokyo and Denver is always 15 hours apart.
What's the current time in MDT?
Right now the time in Mountain Daylight Time (MDT) is Monday, June 29, 2026 · 11:54:04 AM. It ticks every second, so you’re always looking at the live MDT clock.
And what time is it in JST?
And in Japan Standard Time (JST), it’s currently Tuesday, June 30, 2026 · 2:54:04 AM. Compare the two and the 15 hours gap is easy to see.
Planning a meeting across JST and MDT?
For example, a 9:00 AM JST meeting takes place at 6:00 PM MDT (−1 day). The trick is to aim for a slot that lands inside normal working hours on both sides. Once you’ve found a time, hit Share on the converter to copy a link with the time built in — easy to send to a colleague. Juggling three or more zones? The meeting planner highlights the hours that overlap for everyone.
Does daylight saving time change the JST–MDT difference?
The labels JST and MDT are fixed offsets, so the result on this page is always exact. One side switches between standard and summer time while the other stays put, so the real-world gap can shift by an hour for part of the year. It's worth checking which label a region is actually using before you lock in a time.
How accurate is this JST to MDT conversion?
We don’t guess. JST and MDT times are worked out from the official IANA time zone database, the trusted standard that operating systems use worldwide. Because daylight-saving rules and regional offsets do change over time, we track those updates rather than relying on a fixed number — which is exactly where many converters slip up.
Convert JST to other time zones
- UTC Coordinated Universal Time
- GMT Greenwich Mean Time
- EST Eastern Standard Time
- EDT Eastern Daylight Time
- CST Central Standard Time
- CDT Central Daylight Time
- MST Mountain Standard Time
- MDT Mountain Daylight Time
- PST Pacific Standard Time
- PDT Pacific Daylight Time
- AKST Alaska Standard Time
- AKDT Alaska Daylight Time
- HST Hawaii Standard Time
- AST Atlantic Standard Time
- ADT Atlantic Daylight Time
- NST Newfoundland Standard Time
- NDT Newfoundland Daylight Time
- BRT Brasília Time
- ART Argentina Time
- WET Western European Time
- WEST Western European Summer Time
- CET Central European Time
- CEST Central European Summer Time
- EET Eastern European Time
- EEST Eastern European Summer Time
- BST British Summer Time
- IST Irish Standard Time
- MSK Moscow Standard Time
- TRT Turkey Time
- WAT West Africa Time
- CAT Central Africa Time
- EAT East Africa Time
- SAST South Africa Standard Time
- GST Gulf Standard Time
- IST Israel Standard Time
- IDT Israel Daylight Time
- IST India Standard Time
- PKT Pakistan Standard Time
- BDT Bangladesh Standard Time
- ICT Indochina Time
- WIB Western Indonesian Time
- WITA Central Indonesian Time
- WIT Eastern Indonesian Time
- CST China Standard Time
- HKT Hong Kong Time
- SGT Singapore Time
- PHT Philippine Time
- KST Korea Standard Time
- AWST Australian Western Standard Time
- ACST Australian Central Standard Time
- ACDT Australian Central Daylight Time
- AEST Australian Eastern Standard Time
- AEDT Australian Eastern Daylight Time
- NZST New Zealand Standard Time
- NZDT New Zealand Daylight Time
Convert to MDT from other time zones
- UTC Coordinated Universal Time
- GMT Greenwich Mean Time
- EST Eastern Standard Time
- EDT Eastern Daylight Time
- CST Central Standard Time
- CDT Central Daylight Time
- MST Mountain Standard Time
- PST Pacific Standard Time
- PDT Pacific Daylight Time
- AKST Alaska Standard Time
- AKDT Alaska Daylight Time
- HST Hawaii Standard Time
- AST Atlantic Standard Time
- ADT Atlantic Daylight Time
- NST Newfoundland Standard Time
- NDT Newfoundland Daylight Time
- BRT Brasília Time
- ART Argentina Time
- WET Western European Time
- WEST Western European Summer Time
- CET Central European Time
- CEST Central European Summer Time
- EET Eastern European Time
- EEST Eastern European Summer Time
- BST British Summer Time
- IST Irish Standard Time
- MSK Moscow Standard Time
- TRT Turkey Time
- WAT West Africa Time
- CAT Central Africa Time
- EAT East Africa Time
- SAST South Africa Standard Time
- GST Gulf Standard Time
- IST Israel Standard Time
- IDT Israel Daylight Time
- IST India Standard Time
- PKT Pakistan Standard Time
- BDT Bangladesh Standard Time
- ICT Indochina Time
- WIB Western Indonesian Time
- WITA Central Indonesian Time
- WIT Eastern Indonesian Time
- CST China Standard Time
- HKT Hong Kong Time
- SGT Singapore Time
- PHT Philippine Time
- JST Japan Standard Time
- KST Korea Standard Time
- AWST Australian Western Standard Time
- ACST Australian Central Standard Time
- ACDT Australian Central Daylight Time
- AEST Australian Eastern Standard Time
- AEDT Australian Eastern Daylight Time
- NZST New Zealand Standard Time
- NZDT New Zealand Daylight Time
Frequently asked questions
How many hours behind JST is MDT?
MDT is 15 hours behind JST — a fixed 15 hours difference, since both are fixed-offset labels.
What time is it in MDT when it's 12:00 PM JST?
When it's 12:00 PM (noon) JST, it's 9:00 PM MDT the previous day.
Do JST or MDT use daylight saving time?
Japan Standard Time (JST) is a fixed offset with no daylight saving; Mountain Daylight Time (MDT) observes daylight saving, alternating with MST.
Why might the real-world JST–MDT difference change during the year?
The labels JST and MDT are fixed offsets, so this converter is always exact. But Mountain Daylight Time's region switches between standard and summer time, so for part of the year you may actually want JST to MST. Always check which label a region is currently using before you schedule.