Time Difference

Kolkata vs Surabaya Time Difference

Compare the current local time in Kolkata, India and Surabaya, Indonesia.

Live local timeDST awareUTC offsets

From

Kolkata

India

4:12 AM

Mon, Aug 17

UTC+5:30Asia/Kolkata

Difference

1h 30m

Swap

Surabaya

Indonesia

5:42 AM

Mon, Aug 17

UTC+7Asia/Jakarta

Current difference

Surabaya is currently 1 hour 30 minutes ahead of Kolkata.

This difference is calculated using the current UTC offsets for both locations and automatically reflects daylight-saving changes.

24-hour comparison

Compare Kolkata and Surabaya hour by hour

See how a full local day in Kolkata, India maps to Surabaya, Indonesia. TimeInOne automatically accounts for timezone offsets, date changes and daylight-saving transitions.

24-hour day

Best working-hours overlap

9:00 AM – 5:00 PM in Kolkata

corresponds to 10:30 AM – 6:30 PM in Surabaya.

8 hours overlap

Kolkata

Asia/Kolkata

Surabaya

Asia/Jakarta

Availability

12:00 AM

Mon, Aug 17

1:30 AM

Mon, Aug 17

Night

1:00 AM

Mon, Aug 17

2:30 AM

Mon, Aug 17

Night

2:00 AM

Mon, Aug 17

3:30 AM

Mon, Aug 17

Night

3:00 AM

Mon, Aug 17

4:30 AM

Mon, Aug 17

Night

4:00 AM

Mon, Aug 17

5:30 AM

Mon, Aug 17

Night

5:00 AM

Mon, Aug 17

6:30 AM

Mon, Aug 17

Night

6:00 AM

Mon, Aug 17

7:30 AM

Mon, Aug 17

Night

7:00 AM

Mon, Aug 17

8:30 AM

Mon, Aug 17

Possible

8:00 AM

Mon, Aug 17

9:30 AM

Mon, Aug 17

Possible

9:00 AM

Mon, Aug 17

10:30 AM

Mon, Aug 17

Good overlap

10:00 AM

Mon, Aug 17

11:30 AM

Mon, Aug 17

Good overlap

11:00 AM

Mon, Aug 17

12:30 PM

Mon, Aug 17

Good overlap

12:00 PM

Mon, Aug 17

1:30 PM

Mon, Aug 17

Good overlap

1:00 PM

Mon, Aug 17

2:30 PM

Mon, Aug 17

Good overlap

2:00 PM

Mon, Aug 17

3:30 PM

Mon, Aug 17

Good overlap

3:00 PM

Mon, Aug 17

4:30 PM

Mon, Aug 17

Good overlap

4:00 PM

Mon, Aug 17

5:30 PM

Mon, Aug 17

Good overlap

5:00 PM

Mon, Aug 17

6:30 PM

Mon, Aug 17

Possible

6:00 PM

Mon, Aug 17

7:30 PM

Mon, Aug 17

Possible

7:00 PM

Mon, Aug 17

8:30 PM

Mon, Aug 17

Possible

8:00 PM

Mon, Aug 17

9:30 PM

Mon, Aug 17

Night

9:00 PM

Mon, Aug 17

10:30 PM

Mon, Aug 17

Night

10:00 PM

Mon, Aug 17

11:30 PM

Mon, Aug 17

Night

11:00 PM

Mon, Aug 17

12:30 AM

Next day

Tue, Aug 18

Night

Working-hour labels use a general 9:00 AM–6:00 PM schedule. Individual schedules may differ.

On daylight-saving transition dates, a local day can contain 23 or 25 real hours instead of 24.

Call planning

Best time to call Surabaya from Kolkata

Compare typical business hours in Kolkata, India and Surabaya, Indonesia to find a practical time for calls, meetings or international coordination.

Kolkata

9:00 AM – 5:00 PM

India

Best overlap

Surabaya

10:30 AM – 6:30 PM

Indonesia

The best time to call Surabaya from Kolkata is between 9:00 AM and 5:00 PM in Kolkata. This corresponds to 10:30 AM – 6:30 PM in Surabaya.

Other reasonable windows

Kolkata

7:00 AM – 9:00 AM

Surabaya

8:30 AM – 10:30 AM

Kolkata

5:00 PM – 8:00 PM

Surabaya

6:30 PM – 9:30 PM

Recommendations use typical 9:00 AM–6:00 PM business hours and a broader 7:00 AM–9:00 PM acceptable calling window. Individual schedules may differ.

Time difference explained

Kolkata and Surabaya time difference explained

Current local-time relationship

Surabaya is currently 1 hour and 30 minutes ahead of Kolkata.

Kolkata uses Asia/Kolkata and currently has an offset of UTC+5:30. Surabaya uses Asia/Jakarta and currently has an offset of UTC+7.

Working-hours overlap

For a typical 9:00 AM–6:00 PM workday, the cities overlap from 9:00 AM to 4:30 PM in Kolkata, corresponding to 10:30 AM–6:00 PM in Surabaya.

Because UTC offsets can change during the year, always check the selected date when planning an important international call or meeting.

Convert a specific time

Need more than the current difference?

Convert a specific date and local time between Kolkata and Surabaya.

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Local clocks

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Current time in Kolkata Current time in Surabaya

FAQ

Kolkata to Surabaya time difference FAQ

Common questions about the current time difference, UTC offsets, daylight-saving changes and practical calling hours between Kolkata and Surabaya.

What is the time difference between Kolkata and Surabaya?

The current time difference between Kolkata and Surabaya is 1h 30m. Surabaya is currently 1 hour and 30 minutes ahead of Kolkata.

Is Surabaya ahead of or behind Kolkata?

Surabaya is currently 1 hour and 30 minutes ahead of Kolkata.

What time is it in Surabaya when it is 9:00 AM in Kolkata?

Using the current UTC offsets, 9:00 AM in Kolkata corresponds to 10:30 AM in Surabaya. The exact difference can change when daylight-saving rules change.

What is the best time to call Surabaya from Kolkata?

Typical 9:00 AM–6:00 PM business hours overlap between 9:00 AM and 4:30 PM in Kolkata. This corresponds to 10:30 AM–6:00 PM in Surabaya.

Can the time difference between Kolkata and Surabaya change?

Yes. The time difference can change if Kolkata or Surabaya changes its UTC offset because of daylight-saving or other local time-zone rules. TimeInOne uses the IANA zones Asia/Kolkata and Asia/Jakarta for date-aware calculations.