GMT to IOT Time Converter

Convert Greenwich Mean Time (GMT) to Indian Ocean Time (IOT). Both time zones are shown live below; current offset between them is 5 hours ahead.

London · Greenwich Mean Time
06:01:22
Monday, May 11, 2026
GMT+1 · UTC+01:00
Diego Garcia · Indian Ocean Time
11:01:22
Monday, May 11, 2026
GMT+6 · UTC+06:00

Convert a specific time

From: GMT (London)
To: IOT (Diego Garcia)
--:--

Daylight Saving status right now

GMT (Greenwich Mean Time)
Observes DST
Yes
In DST right now
Yes
Next fall back
2026-10-25
Offset shift
UTC+01:00 → UTC+00:00
IOT (Indian Ocean Time)
Observes DST
No

Heads up: GMT observes DST while IOT does not. The 5-hour difference shown above will shift by one hour when GMT starts or ends DST.

When can GMT and IOT meet?

00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
GMT
IOT
Both zones in working hours (9am-5pm)
One zone working
Off-hours
Columns are hours of the day in London (GMT). Each row shows the local working-hours state in that zone for the same moment in time.
3 hours of overlap during standard 9am-5pm working hours.
Best meeting window: 09:00–11:00 GMT (14:00–16:00 IOT).

Hour-by-hour GMT to IOT conversion table

GMT time (London)IOT time (Diego Garcia)Status
00:00 Mon05:00 MonOff-hours both sides
01:00 Mon06:00 MonOff-hours both sides
02:00 Mon07:00 MonOff-hours both sides
03:00 Mon08:00 MonOff-hours both sides
04:00 Mon09:00 MonIOT working
05:00 Mon10:00 MonIOT working
06:00 Mon11:00 MonIOT working
07:00 Mon12:00 MonIOT working
08:00 Mon13:00 MonIOT working
09:00 Mon14:00 MonBoth at work
10:00 Mon15:00 MonBoth at work
11:00 Mon16:00 MonBoth at work
12:00 Mon17:00 MonGMT working
13:00 Mon18:00 MonGMT working
14:00 Mon19:00 MonGMT working
15:00 Mon20:00 MonGMT working
16:00 Mon21:00 MonGMT working
17:00 Mon22:00 MonOff-hours both sides
18:00 Mon23:00 MonOff-hours both sides
19:00 Mon00:00 TueOff-hours both sides
20:00 Mon01:00 TueOff-hours both sides
21:00 Mon02:00 TueOff-hours both sides
22:00 Mon03:00 TueOff-hours both sides
23:00 Mon04:00 TueOff-hours both sides

Times computed for today in each zone using the IANA time zone database. The conversion accounts for daylight saving time wherever applicable.

About these time zones

Greenwich Mean Time (GMT)
IANA identifier
Europe/London
Current UTC offset
UTC+01:00
Current abbreviation
GMT+1
Major cities in this zone
LondonManchesterEdinburghBirmingham
Indian Ocean Time (IOT)
IANA identifier
Indian/Chagos
Current UTC offset
UTC+06:00
Current abbreviation
GMT+6
Major cities in this zone
Diego Garcia

Sun today in London and Diego Garcia

London
Sunrise
05:16
Sunset
20:39
Solar noon
12:58
Daylight
15h 23m

Related converters

IOT to GMT (reverse)GMT to ESTGMT to PSTGMT to UTCGMT to CETGMT to ISTEST to IOTPST to IOTUTC to IOTCET to IOTIST to IOT
Looking for local time? See time in London or time in Diego Garcia.

Frequently asked questions

What is the time difference between GMT and IOT right now?+
IOT (Indian Ocean Time) is currently 5 hours ahead GMT (Greenwich Mean Time). The exact difference can change when one or both zones transition into or out of daylight saving time.
Does GMT or IOT observe daylight saving time?+
GMT: observes daylight saving time. IOT: does not observe daylight saving time.
When is the best time to schedule a meeting between GMT and IOT?+
The strongest overlap is 09:00–11:00 GMT (14:00–16:00 IOT), giving 3 hours when both sides are within standard 9am-5pm working hours.
What time is it in Diego Garcia when it is 12:00 noon in London?+
When it is 12:00 Mon in London (GMT), it is 17:00 Mon in Diego Garcia (IOT).
Which IANA time zone identifiers are used for GMT and IOT?+
GMT maps to "Europe/London" in the IANA database. IOT maps to "Indian/Chagos". These identifiers are what most software libraries use to convert times accurately, including DST handling.
Is London ahead of or behind Diego Garcia?+
Whether London (GMT) is ahead of or behind Diego Garcia (IOT) depends on the current UTC offsets. Right now IOT is 5 hours ahead GMT. The live converter and side-by-side clocks above always reflect the current direction.
What are the current UTC offsets for GMT and IOT?+
GMT is UTC+01:00 (GMT+1) and IOT is UTC+06:00 (GMT+6). Both offsets shift by one hour when the corresponding region enters or exits daylight saving time, so the live values on this page are the source of truth.
Can I schedule meetings during business hours for both GMT and IOT?+
Yes. There are 3 hours of overlap during standard 9am-5pm working hours, with the strongest window at 09:00–11:00 GMT.