Ireland to JST
+8hIreland
ISTSOURCEJST
JSTGreen rows indicate typical business hours (9 AM - 5 PM)
IST and JST on the World Map
The map below highlights the IST (Greenwich Mean Time) and JST (Japan Standard Time) timezone regions across the globe.
GMT – Greenwich Mean Time
UTC+00:00Greenwich Mean Time (GMT) is the mean solar time at the Royal Observatory in Greenwich, London. It is the same as UTC+00:00.
- •GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London.
- •The Royal Observatory in Greenwich has been the reference point for GMT since 1884.
- •GMT and UTC are often used interchangeably, but UTC is based on atomic clocks.
- •Iceland uses GMT year-round and never observes daylight saving time.
- •The UK switches from GMT to BST (British Summer Time) in late March each year.
JST – Japan Standard Time
UTC+09:00Japan Standard Time (JST) is the time zone for Japan, 9 hours ahead of UTC.
- •Japan does not observe daylight saving time.
- •Tokyo is the most populous metropolitan area in the world.
- •The Tokyo Stock Exchange operates from 9:00 AM to 3:00 PM JST.
- •JST is 14 hours ahead of EST and 9 hours ahead of GMT.
Understanding the +8h Gap: Ireland vs JST
Ireland runs on Irish Standard Time (IST) at UTC+01:00, currently observing daylight saving time. JST runs on Japan Standard Time (JST) at UTC+09:00. That puts Ireland 8 hours ahead of JST — a difference of +8h at the current offsets.
In practice, when it is 9:00 AM in Ireland it is 5:00 PM in JST. Midnight in Ireland is 8:00 AM in JST.Ireland observes daylight saving time while JST does not, so the gap narrows or widens by an hour part of the year.
Ireland to JST time conversion table
| Ireland (IST) | JST (JST) | Day |
|---|---|---|
| 12:00 AM | 8:00 AM | same day |
| 6:00 AM | 2:00 PM | same day |
| 7:00 AM | 3:00 PM | same day |
| 8:00 AM | 4:00 PM | same day |
| 9:00 AM | 5:00 PM | same day |
| 12:00 PM | 8:00 PM | same day |
| 3:00 PM | 11:00 PM | same day |
| 5:00 PM | 1:00 AM | next day |
| 6:00 PM | 2:00 AM | next day |
| 9:00 PM | 5:00 AM | next day |
Why people convert Ireland to JST time
- Scheduling a call from Ireland to JST: a 10:00 AM start in Ireland lands at 6:00 PM in JST, so you can confirm the slot without doing the arithmetic yourself.
- Handling a +8h gap: Ireland and JST have no overlap inside a normal 9-to-5 day, so real-time meetings need an early-morning or late-evening slot on one side. 9:00 AM in JST is 5:00 PM in Ireland.
- Keeping family and friends in sync: knowing that 8:00 PM in Ireland is 4:00 AM in JST makes it easy to avoid calling at 3 AM.
- Always state the zone abbreviation, not just the hour. "3:00 PM IST" is unambiguous; "3 PM" across a +8h gap is not.
- With a +8h gap there is no shared 9-to-5 window, so alternate the early start: one week Ireland takes the early slot, the next week JST does.
- Ireland: Clocks fall back on Sun, Oct 25, 2026. Re-check this page after that date because the offset changes and so does the +8h gap.
About GMT (Greenwich Mean Time)
Greenwich Mean Time (GMT) is the clock time at the Royal Observatory in Greenwich, London, which sits on the Prime Meridian (0° longitude). GMT serves as the reference point from which all other time zones are calculated. The United Kingdom uses GMT during winter months and switches to British Summer Time (BST, UTC+01:00) from late March to late October. Several West African nations use GMT year-round. GMT is often used interchangeably with UTC (Coordinated Universal Time), although technically they are different – UTC is based on atomic clocks while GMT is based on Earth's rotation.
About JST (Japan Standard Time)
Japan Standard Time (JST) is the standard time zone for all of Japan. Japan does not observe daylight saving time. JST is 9 hours ahead of UTC and 14 hours ahead of EST. The Tokyo Stock Exchange, the world's third largest by market capitalization, operates on JST. South Korea uses the same offset (KST) but it is a distinct time zone.
Best time to call between Ireland and JST
With a +8h offset there is no overlap inside a normal 9 AM – 5 PM day. JST opens at 9:00 AM JST, which is 5:00 PM in Ireland, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
Ireland and JST have no shared working hours because of the +8h gap. Teams need to alternate early starts or rely on asynchronous handovers.
Ireland is 8 hours ahead of JST (IST UTC+01:00 → JST UTC+09:00). There is no shared 9-to-5 window, so plan around an early or late slot. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
Ireland
☀ Currently in DST
Standard: UTC+00:00 · DST: UTC+01:00
Clocks fall back on Sun, Oct 25, 2026
JST
Does not observe DST
Learn More About Time
Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:
Frequently Asked Questions
What is the time difference between Ireland and JST?
Ireland (IST, UTC+01:00) is 8 hours ahead of JST (JST, UTC+09:00). The gap is currently +8h.
How do I convert Ireland time to JST time?
Add +8h to Ireland local time. For example, 9:00 AM in Ireland is 5:00 PM in JST.
What time is it in JST right now?
JST uses JST at UTC+09:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +8h offset from Ireland.
What is the best time to call JST from Ireland?
There is no shared working-hours window because of the +8h gap. The closest option is 1:00 PM in Ireland, which is 9:00 PM in JST.
Which is ahead, Ireland or JST?
Ireland is 8 hours ahead of JST. When it is 12:00 PM in Ireland it is 8:00 PM in JST.
Do Ireland and JST use different time zones?
Ireland (Ireland) uses IST at UTC+01:00, while JST uses JST at UTC+09:00. The IANA identifiers are Europe/Dublin and Asia/Tokyo.
Does daylight saving time affect the Ireland–JST difference?
Yes at the moment: Ireland is on daylight saving time and JST is not, so the +8h gap shifts by an hour when exactly one of them changes clocks.
Which other cities share Ireland's time zone?
IST also covers London, Dublin, Lisbon, Accra, Reykjavik, Edinburgh, Casablanca, Dakar and 5 more.
Which countries use IST, Ireland's zone?
IST is used in United Kingdom, Ireland, Iceland, Portugal (mainland), Ghana, Senegal, Mali, Mauritania and 7 more.
Is there a day difference between Ireland and JST?
Not normally. The +8h gap only pushes the date over for late-evening times.
What is the time difference between Ireland and JST?
JST is +8h from Ireland.
What timezone is Ireland in?
Ireland operates on its local timezone.
What timezone is JST in?
JST operates on its local timezone.
Which countries use GMT (Greenwich Mean Time)?
GMT is used in United Kingdom, Ireland, Iceland, Portugal (mainland), Ghana, Senegal, and 9 more countries.
Does GMT observe daylight saving time?
Yes, GMT switches to BST during summer months.
What are some interesting facts about GMT?
GMT is based on the Prime Meridian (0° longitude) passing through Greenwich, London. The Royal Observatory in Greenwich has been the reference point for GMT since 1884.
Which cities are in the JST timezone?
Major cities in the JST timezone include Tokyo, Osaka, Yokohama, Nagoya, Sapporo, Kyoto, Kobe, Fukuoka.
What is the UTC offset for JST?
Japan Standard Time (JST) is at UTC+09:00.
What should I know about the JST timezone?
Japan does not observe daylight saving time. Tokyo is the most populous metropolitan area in the world.
When is it midnight in Ireland, what time is it in JST?
When it is 12:00 AM (midnight) in Ireland (GMT), it is +8h later in JST (JST).
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