London to Mumbai Time Converter

Convert any time in London to Mumbai live, with daylight saving on both sides and the working-hour overlap.

Time in Mumbai
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Your result updates live as you type.

Mumbai is 4 hours 30 minutes ahead of London for most of the year: when it is 10:00 am in London it is 2:30 pm in Mumbai. In offset terms London is on UTC+00:00 and Mumbai is on UTC+05:30 in January, and UTC+01:00 and UTC+05:30 in July. The converter above works from your browser’s own time zone data, so the figure it shows is the one in force today rather than the one that was in force when this page was written.

The difference is not constant, because only one of the two cities observes daylight saving. In 2026, London changes on 29 March and 25 October and Mumbai does not change at all. That leaves 3 distinct periods in the year, and the table below gives the exact dates. It is the short windows that catch people out: a recurring call booked in one city’s clock silently moves in the other’s.

For arranging anything, the number that matters is the overlap. London works 09:00 to 17:30 and Mumbai works 10:00 to 18:30, which leaves 09:00 to 14:00 in London — 13:30 to 18:30 in Mumbai — as the window when both are open. That is 5 hours of shared working time. Both cities work Monday to Friday, so only the clock has to be reconciled.

Two local details worth knowing. The City works 09:00 to 17:30, and the 08:00 market open means email is answered well before the official start. India runs on a single half-hour zone, UTC+05:30, for the whole country and does not observe daylight saving.

The safest way to write a time for these two cities is to give both, as in "10:00 London / 14:30 Mumbai", or to give the UTC offset. Abbreviations are the trap: London is on GMT for part of the year and BST for the rest, and the same three letters are reused in other parts of the world for entirely different offsets.

The formula

local Mumbai = local London + 4.5 hours
local London
The time you enter, on the London clock
offset
Each city’s UTC offset at that moment, read live from the IANA time zone database in your browser
+4.5
The difference in hours that holds for most of 2026: Mumbai is 4 hours 30 minutes ahead of London
day shift
Whether the converted time falls on the previous, same or next calendar day in Mumbai

How it works, step by step

  1. Enter a time in London using the 24-hour hour box and the minute box — 15:30 is hour 15, minute 30.
  2. Your browser reports the UTC offset in force in London and in Mumbai for that moment, so a date near a daylight saving transition is handled correctly rather than with a fixed 4.5 hour rule.
  3. The second offset minus the first gives the difference, which is added to the time you entered. A result past midnight is marked as the next or previous day, because that is where most conversion mistakes live.
  4. The panel also shows the current time in both cities, the date in Mumbai, and whether the two offices are open at the same moment.

Worked examples

09:00 in London

09:00 in London is 13:30 in Mumbai — inside Mumbai office hours. In 12-hour terms, 9:00 am against 1:30 pm. Both offices are open at that moment, so it is a slot either side can accept.

12:00 in London

12:00 in London is 16:30 in Mumbai — inside Mumbai office hours. In 12-hour terms, 12:00 pm against 4:30 pm. Both offices are open at that moment, so it is a slot either side can accept.

16:30 in London

16:30 in London is 21:00 in Mumbai — after the Mumbai working day has finished. In 12-hour terms, 4:30 pm against 9:00 pm. Only one of the two offices is open at that moment, so it is worth offering rather than assuming.

The 1 January window, when the usual answer is wrong

Between 1 January and 28 March the difference is +05:30 rather than +04:30, because one city has changed its clocks and the other has not. In that window 10:00 in London is 15:30 in Mumbai, an hour away from where a fixed-offset table would put it.

How to read your score

0–5.999Middle of the night in MumbaiBetween midnight and 06:00 in Mumbai. Nothing scheduled here will be answered; if the time you entered lands in this window, the meeting has to move or one side has to work outside hours.
6–10Early morning in MumbaiBefore the working day starts in Mumbai, which customarily begins at 10:00. Reachable by phone for something urgent, not for a routine call.
10–18.5Office hours in MumbaiInside the 10:00 to 18:30 working day in Mumbai. Whether it also suits London depends on the overlap window given above.
18.5–24Evening in MumbaiAfter 18:30, when the Mumbai working day has finished. Fine for a message, poor for a meeting, and it gets worse the later it runs.

Frequently asked questions

How many hours ahead of London is Mumbai?

Mumbai is 4 hours 30 minutes ahead of London for most of 2026, so 09:00 in London is 13:30 in Mumbai. The difference changes during the daylight saving changeovers, and the table on this page lists every period in the year with its exact dates.

What is 2 pm London time in Mumbai?

6:30 pm, after the Mumbai working day has finished. In 24-hour form 14:00 in London is 18:30 in Mumbai, and that is outside working hours in Mumbai.

What is the best time to call between London and Mumbai?

Anywhere between 09:00 and 14:00 London time, which is 13:30 to 18:30 in Mumbai. Both offices are open across that whole window — 5 hours of it. If you want one answer rather than a range, 11:30 in London is the middle of the overlap.

Is Mumbai ahead of or behind London?

Mumbai is ahead. London is at UTC+00:00 and Mumbai is at UTC+05:30 in mid-January, and UTC+01:00 and UTC+05:30 in mid-July. The clock moves forward going from London to Mumbai, which is why Mumbai reaches the end of its working day first.

Do London and Mumbai change their clocks on the same date?

No. In 2026, London changes on 29 March 2026 and 25 October 2026, and Mumbai does not change its clocks at all. That is why the difference between them takes 2 different values across the year rather than one.

What do the abbreviations for London mean?

London is on GMT in winter and BST in summer, while Mumbai uses IST and IST. Abbreviations are the least reliable way to write a time: several are ambiguous between regions, and the summer and winter forms are an hour apart. A UTC offset, or the time given in both cities, cannot be misread.

Does this converter stay correct after the clocks change?

Yes. It does not use a stored number for the difference. Each time you change a value it asks your browser for the UTC offset that Europe/London and Asia/Kolkata are on at that moment, using the IANA time zone database that ships with your operating system, and takes the difference. The tables on this page are computed from the same database for 2026.

London to Mumbai: every hour, every period of 2026, and meeting slots

London to Mumbai, hour by hour
London (24h)London (12h)Mumbai (24h)Mumbai (12h)Status
00:0012:00 am04:304:30 amoutside office hours
01:001:00 am05:305:30 amoutside office hours
02:002:00 am06:306:30 amoutside office hours
03:003:00 am07:307:30 amoutside office hours
04:004:00 am08:308:30 amoutside office hours
05:005:00 am09:309:30 amoutside office hours
06:006:00 am10:3010:30 amoffice hours in Mumbai
07:007:00 am11:3011:30 amoffice hours in Mumbai
08:008:00 am12:3012:30 pmoffice hours in Mumbai
09:009:00 am13:301:30 pmoffice hours in both
10:0010:00 am14:302:30 pmoffice hours in both
11:0011:00 am15:303:30 pmoffice hours in both
12:0012:00 pm16:304:30 pmoffice hours in both
13:001:00 pm17:305:30 pmoffice hours in both
14:002:00 pm18:306:30 pmoffice hours in London
15:003:00 pm19:307:30 pmoffice hours in London
16:004:00 pm20:308:30 pmoffice hours in London
17:005:00 pm21:309:30 pmoffice hours in London
18:006:00 pm22:3010:30 pmoutside office hours
19:007:00 pm23:3011:30 pmoutside office hours
20:008:00 pm00:30 (next day)12:30 am (next day)outside office hours
21:009:00 pm01:30 (next day)1:30 am (next day)outside office hours
22:0010:00 pm02:30 (next day)2:30 am (next day)outside office hours
23:0011:00 pm03:30 (next day)3:30 am (next day)outside office hours

Computed at a difference of 4.5 hours, which is the one that holds for most of 2026. During the transition windows in the table below, shift the right-hand columns by an hour.

The London to Mumbai difference through 2026
PeriodLengthLondon offsetMumbai offsetDifferenceAbbreviations
01 Jan to 28 Mar87 daysUTC+00:00UTC+05:30+5:30GMT / IST
29 Mar to 24 Oct210 daysUTC+01:00UTC+05:30+4:30BST / IST
25 Oct to 31 Dec68 daysUTC+00:00UTC+05:30+5:30GMT / IST

Every row is read from the IANA time zone database. Short periods appear where one city has changed its clocks and the other has not yet done so.

Meeting slots between London and Mumbai
London12-hourMumbaiVerdict
06:006:00 am10:30Too early in London
06:306:30 am11:00Too early in London
07:007:00 am11:30Too early in London
07:307:30 am12:00Too early in London
08:008:00 am12:30Too early in London
08:308:30 am13:00Too early in London
09:009:00 am13:30Good — both offices open
09:309:30 am14:00Good — both offices open
10:0010:00 am14:30Good — both offices open
10:3010:30 am15:00Good — both offices open
11:0011:00 am15:30Good — both offices open
11:3011:30 am16:00Good — both offices open
12:0012:00 pm16:30Good — both offices open
12:3012:30 pm17:00Good — both offices open
13:001:00 pm17:30Good — both offices open
13:301:30 pm18:00Good — both offices open
14:002:00 pm18:30After hours in Mumbai
14:302:30 pm19:00After hours in Mumbai
15:003:00 pm19:30After hours in Mumbai
15:303:30 pm20:00After hours in Mumbai
16:004:00 pm20:30After hours in Mumbai
16:304:30 pm21:00After hours in Mumbai
17:005:00 pm21:30After hours in Mumbai
17:305:30 pm22:00Outside both
18:006:00 pm22:30Outside both
18:306:30 pm23:00Outside both
19:007:00 pm23:30Outside both
19:307:30 pm00:00 (next day)Outside both
20:008:00 pm00:30 (next day)Outside both
20:308:30 pm01:00 (next day)Outside both
21:009:00 pm01:30 (next day)Outside both
21:309:30 pm02:00 (next day)Outside both

Office hours taken as 09:00–17:30 in London and 10:00–18:30 in Mumbai, which are the customary hours in each city rather than a generic nine to five.

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