GST to IST
Convert Gulf Standard Time (GST) to India Standard Time (IST) and back. Right now Kolkata is 1 hours 30 minutes ahead of Dubai. Daylight saving is applied for the date being converted, not for today.
| Zone | 00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | Copy |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dubai | 00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | |
| Kolkata | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 00 +1d | |
| UTC | 20 -1d | 21 -1d | 22 -1d | 23 -1d | 00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | |
09–17 working hours 07–09 shoulder 23–06 night Hover an hour to convert it · click to pin it, then copy any row
How far apart Dubai and Kolkata really are
Kolkata is 1 hours 30 minutes ahead of Dubai, and that holds for every day of the year. Neither zone shifts relative to the other, so a single remembered offset is safe for this pair — which is unusual, and worth knowing.
Working-hours overlap
Treating 09:00–17:00 as the working day in both places, there are 7 hours of overlap: 9:00 am, 10:00 am, 11:00 am, 12:00 pm, 1:00 pm, 2:00 pm, 3:00 pm in Dubai, which is 10:30 am, 11:30 am, 12:30 pm, 1:30 pm, 2:30 pm, 3:30 pm, 4:30 pm in Kolkata. Those are the slots to aim for; everything else costs someone their evening.
Dubai to Kolkata, hour by hour
Every hour of Dubai's day and the matching local time in Kolkata, for 22 Oct 2026. Rows where both cities are inside working hours are marked.
| Dubai (GST) | Kolkata (IST) | Both working? |
|---|---|---|
| 12:00 am | 1:30 am | — |
| 1:00 am | 2:30 am | — |
| 2:00 am | 3:30 am | — |
| 3:00 am | 4:30 am | — |
| 4:00 am | 5:30 am | — |
| 5:00 am | 6:30 am | — |
| 6:00 am | 7:30 am | — |
| 7:00 am | 8:30 am | — |
| 8:00 am | 9:30 am | — |
| 9:00 am | 10:30 am | Yes |
| 10:00 am | 11:30 am | Yes |
| 11:00 am | 12:30 pm | Yes |
| 12:00 pm | 1:30 pm | Yes |
| 1:00 pm | 2:30 pm | Yes |
| 2:00 pm | 3:30 pm | Yes |
| 3:00 pm | 4:30 pm | Yes |
| 4:00 pm | 5:30 pm | — |
| 5:00 pm | 6:30 pm | — |
| 6:00 pm | 7:30 pm | — |
| 7:00 pm | 8:30 pm | — |
| 8:00 pm | 9:30 pm | — |
| 9:00 pm | 10:30 pm | — |
| 10:00 pm | 11:30 pm | — |
| 11:00 pm | 12:30 am next day | — |
Why you should store the zone, not the offset
Even though this pair happens to keep a constant gap today, that is a property of current legislation rather than a guarantee. Store Asia/Dubai and Asia/Kolkata — the IANA
identifiers — alongside any time a user entered locally. The identifier
carries the zone's entire history of rule changes, so a date from 1995
converts with the rules that were in force in 1995.
Internally, keep the instant as a Unix timestamp. The epoch value is identical in Dubai, Kolkata and everywhere else; the zone is applied only at the edges, when a human needs to read it. The current Unix timestamp is at the top of this page, and the zones versus offsets guide explains why the distinction bites.
Related conversions
Frequently asked questions
What time is it in Kolkata when it is 9:00 am in Dubai?
9:00 am GST is 10:30 am in Kolkata. The full hour-by-hour table on this page covers every other hour of the day.
How many hours ahead is IST of GST?
Kolkata is 1 hours 30 minutes ahead of Dubai, and that gap holds all year — neither zone shifts relative to the other, so a single number is safe to remember for this pair.
Is IST to GST the same conversion in reverse?
Yes — subtract instead of add. If Kolkata is 1 hours 30 minutes ahead of Dubai, then Dubai is the same interval behind Kolkata. The grid on this page reads in both directions, which is why /ist-to-gst leads here rather than to a separate page.
When can Dubai and Kolkata meet during working hours?
There are 7 hours when both cities are inside 09:00–17:00: 9:00 am GST, 10:00 am GST, 11:00 am GST, 12:00 pm GST, 1:00 pm GST, 2:00 pm GST, 3:00 pm GST. The green cells in the grid above show the same thing visually.
Does Dubai or Kolkata observe daylight saving time?
Dubai does not — it stays on UTC+04:00 all year. Kolkata does not — it stays on UTC+05:30 all year.