What is the time difference between Kolkata and Tokyo?

Tokyo is 3 hours 30 minutes ahead of Kolkata. That figure is current — it changes by an hour when either city starts or ends daylight saving, and the exact dates are listed above.

When is the best time to call Tokyo from Kolkata?

Between 09:00–14:30 in Kolkata, which is 12:30–18:00 in Tokyo. That is the only stretch where both cities are inside a 09:00–18:00 day.

Does Kolkata observe daylight saving time?

No. Kolkata stays on UTC+5:30 all year, so its clocks never move.

Does Tokyo observe daylight saving time?

No. Tokyo stays on UTC+9 all year, so its clocks never move.

If it is midday in Kolkata, what time is it in Tokyo?

It is 15:30 in Tokyo, on the same calendar date. That holds for the current offsets; it does not change through the year, because neither city moves its clocks.

Which time zones do Kolkata and Tokyo use?

Kolkata uses Asia/Kolkata, currently UTC+5:30 (IST), and Tokyo uses Asia/Tokyo, currently UTC+9. Those identifiers are the ones to use in code — abbreviations are ambiguous and offsets change.

Convert Kolkata time to Tokyo time

Tokyo is 3 hours 30 minutes ahead of Kolkata right now, so midday in Kolkata lands in the afternoon in Tokyo.

Convert a time

From

Date

Time

Converted time

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The converter needs JavaScript to run. Everything below — offsets, daylight saving dates and the hour-by-hour table — is part of the page and works without it.

Hour by hour

Every hour of a day in Kolkata, and what the clock reads in Tokyo at that same moment.

Kolkata	Tokyo
00:00	03:30
01:00	04:30
02:00	05:30
03:00	06:30
04:00	07:30
05:00	08:30
06:00	09:30
07:00	10:30
08:00	11:30
09:00	12:30
10:00	13:30
11:00	14:30
12:00	15:30
13:00	16:30
14:00	17:30
15:00	18:30
16:00	19:30
17:00	20:30
18:00	21:30
19:00	22:30
20:00	23:30
21:00	00:30next day
22:00	01:30next day
23:00	02:30next day

Daylight saving time

Both cities keep one offset all year. Whatever difference holds today still holds in six months.

Kolkata

Does not observe daylight saving time

Standard: UTC+5:30

Tokyo

Does not observe daylight saving time

Standard: UTC+9

When you can actually talk

The window is 5 hours 30 minutes wide — 09:00–14:30 in Kolkata, 12:30–18:00 in Tokyo.

Kolkata 09:00–14:30Tokyo 12:30–18:00

Reference

The zone identifiers and offsets behind everything above.

	Kolkata	Tokyo
IANA zone	Asia/Kolkata	Asia/Tokyo
Abbreviation	IST	UTC+9
Standard offset	UTC+5:30	UTC+9
Daylight offset	—	—
Clock changes this year	0	0
Country	India	Japan

Example, not the current time. Live times appear once the page loads.

Common questions

What is the time difference between Kolkata and Tokyo?: Tokyo is 3 hours 30 minutes ahead of Kolkata. That figure is current — it changes by an hour when either city starts or ends daylight saving, and the exact dates are listed above.
When is the best time to call Tokyo from Kolkata?: Between 09:00–14:30 in Kolkata, which is 12:30–18:00 in Tokyo. That is the only stretch where both cities are inside a 09:00–18:00 day.
Does Kolkata observe daylight saving time?: No. Kolkata stays on UTC+5:30 all year, so its clocks never move.
Does Tokyo observe daylight saving time?: No. Tokyo stays on UTC+9 all year, so its clocks never move.
If it is midday in Kolkata, what time is it in Tokyo?: It is 15:30 in Tokyo, on the same calendar date. That holds for the current offsets; it does not change through the year, because neither city moves its clocks.
Which time zones do Kolkata and Tokyo use?: Kolkata uses Asia/Kolkata, currently UTC+5:30 (IST), and Tokyo uses Asia/Tokyo, currently UTC+9. Those identifiers are the ones to use in code — abbreviations are ambiguous and offsets change.