Colombo to Dublin
-4h 30mColombo
ISTSOURCEDublin
ISTGreen rows indicate typical business hours (9 AM - 5 PM)
IST and IST on the World Map
The map below highlights the IST (India Standard Time) and IST (Greenwich Mean Time) timezone regions across the globe.
IST – India Standard Time
UTC+05:30India Standard Time (IST) is the time zone for India and Sri Lanka, 5 hours and 30 minutes ahead of UTC.
- •India is 10 hours 30 minutes ahead of EST and 5 hours 30 minutes ahead of GMT.
- •India uses a single time zone despite spanning 30° of longitude.
- •IST is one of only a handful of time zones with a 30-minute offset.
- •IST is the most populous single time zone in the world with over 1.4 billion people.
- •The Bombay Stock Exchange (BSE) and National Stock Exchange (NSE) operate on IST.
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.
About Colombo
WikipediaColombo operates on Sri Lanka Time (SLST), UTC+5:30. Sharing India's timezone, Colombo is a key South Asian trade and tourism hub.
Sri Lanka Standard Time (SLST) uses UTC+5:30, same offset as India.
Everything You Need to Know About Colombo and Dublin Time
Colombo runs on India Standard Time (IST) at UTC+05:30. Dublin runs on Irish Standard Time (IST) at UTC+01:00, also currently on daylight saving time. That puts Colombo 4 hours 30 minutes behind Dublin — a difference of -4h 30m at the current offsets.
In practice, when it is 9:00 AM in Colombo it is 4:30 AM in Dublin. Midnight in Colombo is 7:30 PM in Dublin.Dublin observes daylight saving time while Colombo does not, so the gap narrows or widens by an hour part of the year.
Colombo to Dublin time conversion table
| Colombo (IST) | Dublin (IST) | Day |
|---|---|---|
| 12:00 AM | 7:30 PM | previous day |
| 6:00 AM | 1:30 AM | same day |
| 7:00 AM | 2:30 AM | same day |
| 8:00 AM | 3:30 AM | same day |
| 9:00 AM | 4:30 AM | same day |
| 12:00 PM | 7:30 AM | same day |
| 3:00 PM | 10:30 AM | same day |
| 5:00 PM | 12:30 PM | same day |
| 6:00 PM | 1:30 PM | same day |
| 9:00 PM | 4:30 PM | same day |
Why people convert Colombo to Dublin time
- Scheduling a call from Colombo to Dublin: a 10:00 AM start in Colombo lands at 5:30 AM in Dublin, so you can confirm the slot without doing the arithmetic yourself.
- Finding shared working hours: both Colombo and Dublin are inside the 9-to-5 working day between 1:30 PM and 5:00 PM IST time (9:00 AM–12:30 PM IST). That is roughly 3 hours 30 minutes of usable overlap.
- Coordinating a Colombo-based team with Dublin contacts: quoting times in the other side's local clock — not your own — removes the single biggest source of missed meetings.
- Always state the zone abbreviation, not just the hour. "3:00 PM IST" is unambiguous; "3 PM" across a -4h 30m gap is not.
- Block 1:30 PM–5:00 PM IST as the recurring meeting window if you work primarily from Colombo and need Dublin colleagues present.
- Dublin: Clocks fall back on Sun, Oct 25, 2026. Any meeting series spanning that date will shift by an hour in local time.
About IST (India Standard Time)
India Standard Time (IST) is the time observed throughout India and Sri Lanka. It is based on the 82.5°E meridian, passing through Mirzapur in Uttar Pradesh. India uses a single time zone despite spanning roughly 30° of longitude, which has been debated. IST does not observe daylight saving time. India is the world's most populous country, making IST one of the most-used time zones globally. The IT outsourcing industry and call centers operate primarily on IST, making the EST-to-IST conversion one of the most searched timezone conversions.
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.
Best time to call between Colombo and Dublin
Both Colombo and Dublin sit inside the 9 AM – 5 PM working day between 1:30 PM–5:00 PM IST, which is 9:00 AM–12:30 PM IST. That gives roughly 3 hours and 30 minutes of shared time — the safest window for a live call or meeting.
Business hours overlap
Colombo and Dublin overlap for about 3 hours during the working day — enough for meetings if you avoid the edges of the window.
Colombo is 4 hours 30 minutes behind Dublin (IST UTC+05:30 → IST UTC+01:00). The shared working window is 1:30 PM–5:00 PM IST. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
Colombo
Does not observe DST
Dublin
☀ Currently in DST
Standard: UTC+00:00 · DST: UTC+01:00
Clocks fall back on Sun, Oct 25, 2026
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 Colombo and Dublin?
Colombo (IST, UTC+05:30) is 4 hours 30 minutes behind Dublin (IST, UTC+01:00). The gap is currently -4h 30m.
How do I convert Colombo time to Dublin time?
Add -4h 30m to Colombo local time. For example, 9:00 AM in Colombo is 4:30 AM in Dublin.
What time is it in Dublin right now?
Dublin uses IST at UTC+01:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -4h 30m offset from Colombo.
What is the best time to call Dublin from Colombo?
Call between 1:30 PM and 5:00 PM IST — that maps to 9:00 AM–12:30 PM IST and keeps both parties inside the working day.
Which is behind, Colombo or Dublin?
Colombo is 4 hours 30 minutes behind Dublin. When it is 12:00 PM in Colombo it is 7:30 AM in Dublin.
Do Colombo and Dublin use different time zones?
Colombo (Sri Lanka) uses IST at UTC+05:30, while Dublin (Ireland) uses IST at UTC+01:00. The IANA identifiers are Asia/Colombo and Europe/Dublin.
Does daylight saving time affect the Colombo–Dublin difference?
Yes at the moment: Dublin is on daylight saving time and Colombo is not, so the -4h 30m gap shifts by an hour when exactly one of them changes clocks.
Which other cities share Colombo's time zone?
IST also covers Mumbai, Delhi, Bangalore, Kolkata, Chennai, Hyderabad, Pune, Ahmedabad and 4 more.
Which countries use IST, Colombo's zone?
IST is used in India, Sri Lanka.
Is there a day difference between Colombo and Dublin?
Not normally. The -4h 30m gap only pushes the date over the previous day.
What is the time difference between Colombo and Dublin?
Dublin is -4h 30m from Colombo.
What timezone is Colombo in?
Colombo operates on Sri Lanka Time (SLST), UTC+5:30. Sharing India's timezone, Colombo is a key South Asian trade and tourism hub.
What timezone is Dublin in?
Dublin operates on its local timezone.
What are the business hours in Colombo?
Standard business hours in Colombo are 9:00 AM - 5:00 PM IST.
Which countries use IST (India Standard Time)?
IST is used in India, Sri Lanka.
Does IST observe daylight saving time?
No, IST does not observe daylight saving time and remains at UTC+05:30 year-round.
What are some interesting facts about IST?
India is 10 hours 30 minutes ahead of EST and 5 hours 30 minutes ahead of GMT. India uses a single time zone despite spanning 30° of longitude.
Which cities are in the GMT timezone?
Major cities in the GMT timezone include London, Dublin, Lisbon, Accra, Reykjavik, Edinburgh, Casablanca, Dakar.
What is the UTC offset for GMT?
Greenwich Mean Time (GMT) is at UTC+00:00. During daylight saving time, it shifts to BST.
What should I know about the GMT timezone?
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.
When is it midnight in Colombo, what time is it in Dublin?
When it is 12:00 AM (midnight) in Colombo (IST), it is -4h 30m later in Dublin (GMT).
Related Developer Tools
Explore more tools that work great with timezone conversions for international teams:
Related Timezone Conversions
More Colombo time conversions
- colombo to sri lanka
- colombo to dubai
- colombo to mumbai
- colombo to delhi
- colombo to bangalore
- colombo to kathmandu
- colombo to bangkok
- colombo to singapore
- colombo to hong kong
- colombo to shanghai
- colombo to beijing
- colombo to tokyo
- colombo to osaka
- colombo to new york
- colombo to london
- colombo to sydney
- colombo to los angeles
- colombo to paris
- colombo to berlin
- colombo to toronto
- new york to colombo
- london to colombo
- dubai to colombo
- tokyo to colombo
- singapore to colombo
- sydney to colombo
- los angeles to colombo
- paris to colombo
- delhi to colombo
- mumbai to colombo
- berlin to colombo
- hong kong to colombo
- toronto to colombo
- kathmandu to colombo
See every conversion from Colombo →·See every conversion from Dublin →