India Standard Time (ist) is used in India. The IANA timezone identifier is Asia/Kolkata.

Arabia Standard Time (ast) is used in Saudi Arabia. The IANA timezone identifier is Asia/Riyadh.

IST to AST Time Converter

India Standard Time → Arabia Standard Time

IST = UTC+5:30AST = UTC+3

⚠️ IST is ambiguous — on this page it means India Standard Time. It also refers to:

Ireland Standard Time (Dublin) → AST ↗Israel Standard Time (Jerusalem) → AST ↗

⚠️ AST is ambiguous — on this page it means Arabia Standard Time. It also refers to:

IST → Atlantic Standard Time (Halifax) ↗

ClockinSync

BASE

09:00

Work Clients Team +

00:0006:0012:0018:0024:00

AST (Riyadh)

Saudi Arabia · -2.5h

06:30

London

United Kingdom · -4.5h

04:30

New York

USA · -9.5h

23:30-1 day

Tokyo

Japan · +3.5h

12:30

Dubai

United Arab Emirates · -1.5h

07:30

How far apart are IST (Mumbai) and AST (Riyadh)?

IST (Mumbai) is 2 hours 30 minutes ahead of AST (Riyadh). Midday in IST (Mumbai) lines up with 09:00 in AST (Riyadh).

IST (Mumbai) runs on Asia/Kolkata; AST (Riyadh) runs on Asia/Riyadh. Together they are 2.5 hours 30 minutes apart.

Daily overlap window

There is a 5.5-hour window each day where both IST (Mumbai) and AST (Riyadh) are within standard business hours (09:00–17:00).

00:0006:0012:0018:0024:00

IST (Mumbai)

AST (Riyadh)

Overlap (5.5h)

Best times to schedule a meeting

There is a 5.5-hour daily window where both locations are in business hours. The 3 best slots are listed below.

12:00 Mumbai / 09:00 Riyadh✓ Both working

13:00 Mumbai / 10:00 Riyadh✓ Both working

14:00 Mumbai / 11:00 Riyadh✓ Both working

Working hours defined as 09:00–17:00 local time for each location.

How to work with IST (Mumbai) and AST (Riyadh) time zones

The 2.5-hour gap between IST (Mumbai) (India) and AST (Riyadh) (Saudi Arabia) requires some planning — but a 5.5-hour daily overlap means both teams can connect in real time without unusual scheduling.

💡 How to schedule across these time zones

✅

If you are in IST (Mumbai), aim for 12:00–13:00, which corresponds to 09:00–10:00 in AST (Riyadh) — both teams are within working hours.

✅

If you are in IST (Mumbai), aim for 13:00–14:00, which corresponds to 10:00–11:00 in AST (Riyadh) — both teams are within working hours.

✅

If you are in IST (Mumbai), aim for 14:00–15:00, which corresponds to 11:00–12:00 in AST (Riyadh) — both teams are within working hours.

Avoid scheduling mistakes — especially around daylight saving changes. Use the ClockinSync Chrome Extension to instantly verify and compare both time zones directly in your browser, without manual calculations.

Add to your browser — Free →

Need a specific time? Use the slider or type directly into the input bar — it understands "3pm", "15:30", and location-specific formats like "9am IST (Mumbai)".

IST (Mumbai) ↔ AST (Riyadh)

5h of business hours overlap daily (09:00–17:00)

IST (Mumbai)

AST (Riyadh)

00:00

21:30-1d

01:00

22:30-1d

02:00

23:30-1d

03:00

00:30

04:00

01:30

05:00

02:30

06:00

03:30

07:00

04:30

08:00

05:30

09:00Working

06:30off

10:00Working

07:30off

11:00Working

08:30off

12:00Working

09:30Working

13:00Working

10:30Working

14:00Working

11:30Working

15:00Working

12:30Working

16:00Working

13:30Working

17:00

14:30Working

18:00

15:30Working

19:00

16:30Working

20:00

17:30

21:00

18:30

22:00

19:30

23:00

20:30

Working hours: 09:00–17:00 local. Green = both working. Purple = one side only.

Frequently Asked Questions

What is the difference between ist and ast?

India Standard Time (ist) is UTC+5:30 and Arabia Standard Time (ast) is UTC+3. The difference between them is 2.5 hours.

Where is ist used?

India Standard Time (ist) is used in India and surrounding regions. The IANA timezone identifier is Asia/Kolkata. Note: ist is ambiguous and may refer to other timezones.

Where is ast used?

Arabia Standard Time (ast) is used in Saudi Arabia and surrounding regions. The IANA timezone identifier is Asia/Riyadh. Note: ast is ambiguous and may refer to other timezones.

How do I convert ist to ast?

Use the interactive converter above. Drag the time slider to any ist time and the ast equivalent updates instantly. You can also type a time like "3pm" or "15:00" in the input bar.

Popular IST conversions

IST → London IST → New York IST → Tokyo IST → Dubai IST → Sydney IST → Paris IST → Berlin IST → Singapore IST → Los Angeles IST → Toronto

Popular AST conversions

London → AST New York → AST Tokyo → AST Dubai → AST Sydney → AST Paris → AST Berlin → AST Singapore → AST Los Angeles → AST Toronto → AST