Greenwich Mean Time (gmt) is used in United Kingdom. The IANA timezone identifier is Europe/London.

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

GMT to AST Time Converter

Greenwich Mean Time → Arabia Standard Time

GMT = UTC+1AST = UTC+3

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

GMT → Atlantic Standard Time (Halifax) ↗

ClockinSync

BASE

09:00

Work Clients Team +

00:0006:0012:0018:0024:00

AST (Riyadh)

Saudi Arabia · +2h

11:00

New York

USA · -5h

04:00

Tokyo

Japan · +8h

17:00

Dubai

United Arab Emirates · +3h

12:00

Sydney

Australia · +9h

18:00

GMT (London) to AST (Riyadh) — exact time difference

GMT (London) is 2 hours behind AST (Riyadh). Midday in GMT (London) lines up with 14:00 in AST (Riyadh).

GMT (London) is in the Europe/London timezone. AST (Riyadh) is in Asia/Riyadh. The difference is 2 hours.

Working hours overlap

There is a 6-hour window each day where both GMT (London) and AST (Riyadh) are within standard business hours (09:00–17:00).

00:0006:0012:0018:0024:00

GMT (London)

AST (Riyadh)

Overlap (6h)

When to schedule across time zones

Both GMT (London) and AST (Riyadh) are in standard hours simultaneously for 6h per day. 3 recommended slots shown below.

09:00 London / 11:00 Riyadh✓ Both working

10:00 London / 12:00 Riyadh✓ Both working

11:00 London / 13:00 Riyadh✓ Both working

Based on standard 09:00–17:00 working hours in each location's local time.

Upcoming public holidays

GMT (London)7 holidays

Jun 15World Cup Bank HolidaySOON

Jul 13Battle of the Boyne

Aug 3Summer Bank Holiday

Aug 31Summer Bank Holiday

Nov 30Saint Andrew's Day

AST (Riyadh)

No upcoming public holidays this year.

How to work with GMT (London) and AST (Riyadh) time zones

Working across GMT (London) (United Kingdom) and AST (Riyadh) (Saudi Arabia) involves a 2-hour gap. The good news: there is a 6-hour mutual window in standard business hours that lets both sides collaborate without anyone joining at an unreasonable hour.

💡 How to schedule across these time zones

✅

09:00–10:00 in GMT (London) = 11:00–12:00 in AST (Riyadh). Both sides are in standard business hours during this window.

✅

10:00–11:00 in GMT (London) = 12:00–13:00 in AST (Riyadh). Both sides are in standard business hours during this window.

✅

11:00–12:00 in GMT (London) = 13:00–14:00 in AST (Riyadh). Both sides are in standard business hours during this window.

DST transitions can silently shift your meeting times by an hour. The ClockinSync Chrome Extension tracks these changes automatically so you never get caught off guard.

Get the Extension — Free →

Use the time slider above to find the exact equivalent time for any moment in GMT (London). The input bar accepts natural language like "3pm", "15:30", or "9am Rome" for instant conversions.

GMT (London) ↔ AST (Riyadh)

6h of business hours overlap daily (09:00–17:00)

GMT (London)

AST (Riyadh)

00:00

02:00

01:00

03:00

02:00

04:00

03:00

05:00

04:00

06:00

05:00

07:00

06:00

08:00

07:00

09:00Working

08:00

10:00Working

09:00Working

11:00Working

10:00Working

12:00Working

11:00Working

13:00Working

12:00Working

14:00Working

13:00Working

15:00Working

14:00Working

16:00Working

15:00Working

17:00off

16:00Working

18:00off

17:00

19:00

18:00

20:00

19:00

21:00

20:00

22:00

21:00

23:00

22:00

00:00+1d

23:00

01:00+1d

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

Frequently Asked Questions

What is the difference between gmt and ast?

Greenwich Mean Time (gmt) is UTC+1 and Arabia Standard Time (ast) is UTC+3. The difference between them is 2 hours.

Where is gmt used?

Greenwich Mean Time (gmt) is used in United Kingdom and surrounding regions. The IANA timezone identifier is Europe/London.

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 gmt to ast?

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

Popular GMT conversions

GMT → New York GMT → Tokyo GMT → Dubai GMT → Sydney GMT → Paris GMT → Berlin GMT → Singapore GMT → Los Angeles GMT → Toronto GMT → Mumbai

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