What is the time difference between Delhi and Kolkata?

There is none. Both cities are in the Asia/Kolkata time zone, so their clocks always read the same and change together.

When is the best time to call Kolkata from Delhi?

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

Does Delhi observe daylight saving time?

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

Does Kolkata observe daylight saving time?

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

Convert Delhi time to Kolkata time

Delhi and Kolkata are on the same clock: both keep Asia/Kolkata time, so there is never a difference between them.

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

The whole day mapped across: read down the left for Delhi, across for Kolkata.

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

Daylight saving time

Neither Delhi nor Kolkata changes its clocks, so the difference between them is the same every day of the year.

Delhi

Does not observe daylight saving time

Standard: UTC+5:30

Kolkata

Does not observe daylight saving time

Standard: UTC+5:30

When you can actually talk

You have 9 hours of shared working time: 09:00–18:00 in Delhi, which is 09:00–18:00 in Kolkata.

Delhi 09:00–18:00Kolkata 09:00–18:00

Reference

The underlying data, in case you need to put it in a calendar invitation or a configuration file.

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

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

Common questions

What is the time difference between Delhi and Kolkata?: There is none. Both cities are in the Asia/Kolkata time zone, so their clocks always read the same and change together.
When is the best time to call Kolkata from Delhi?: Between 09:00–18:00 in Delhi, which is 09:00–18:00 in Kolkata. That is the only stretch where both cities are inside a 09:00–18:00 day.
Does Delhi observe daylight saving time?: No. Delhi stays on UTC+5:30 all year, so its clocks never move.
Does Kolkata observe daylight saving time?: No. Kolkata stays on UTC+5:30 all year, so its clocks never move.