Offset
The time difference between Adelaide and Riyadh is 6.5 hours.
Adelaide (ACST) is ahead of Riyadh (AST).
ACST: UTC+9:30
AST: UTC+3
Neither Adelaide nor Riyadh is currently observing daylight saving time.
When to schedule
Business-hours overlap: 4 PM–5 PM in Adelaide (9 AM–10 AM in Riyadh).
Both teams are in working hours during this window on weekdays.
Suggested time: 4:00 PM Adelaide (9:30 AM Riyadh).
This window may shift by an hour during daylight saving time.
Note: the working week in Saudi Arabia runs Sunday–Thursday; Friday–Saturday is the weekend, so overlap on those days is limited.
Public holidays in 2026
National public holidays can affect availability — a counterpart is likely off work on their own holidays, so it's worth planning meetings and deadlines around them.
Australia
- New Year's DayThu, Jan 1
- Australia DayMon, Jan 26
- Good FridayFri, Apr 3
- Easter MondayMon, Apr 6
- Christmas DayFri, Dec 25
- St. Stephen's DayMon, Dec 28
About these zones
Quick reference
Full 24-hour conversion table — tap any time to open it in the converter.
| Adelaide | Riyadh | Day |
|---|---|---|
| 12:00 am | 5:30 pm | -1 day |
| 1:00 am | 6:30 pm | -1 day |
| 2:00 am | 7:30 pm | -1 day |
| 3:00 am | 8:30 pm | -1 day |
| 4:00 am | 9:30 pm | -1 day |
| 5:00 am | 10:30 pm | -1 day |
| 6:00 am | 11:30 pm | -1 day |
| 7:00 am | 12:30 am | Same day |
| 8:00 am | 1:30 am | Same day |
| 9:00 am | 2:30 am | Same day |
| 10:00 am | 3:30 am | Same day |
| 11:00 am | 4:30 am | Same day |
| 12:00 pm | 5:30 am | Same day |
| 1:00 pm | 6:30 am | Same day |
| 2:00 pm | 7:30 am | Same day |
| 3:00 pm | 8:30 am | Same day |
| 4:00 pm | 9:30 am | Same day |
| 5:00 pm | 10:30 am | Same day |
| 6:00 pm | 11:30 am | Same day |
| 7:00 pm | 12:30 pm | Same day |
| 8:00 pm | 1:30 pm | Same day |
| 9:00 pm | 2:30 pm | Same day |
| 10:00 pm | 3:30 pm | Same day |
| 11:00 pm | 4:30 pm | Same day |
Daylight saving time
Adelaide observes daylight saving time; Riyadh does not. The offset between the two zones changes when Adelaide transitions: on Sunday, October 4, 2026, clocks spring forward from ACST to ACDT.
See the daylight saving time page for transition dates across every time zone.
Daylight today
- Sunrise
- 7:19 AM
- Sunset
- 5:12 PM
- Day length
- 9h 53m
- Sunrise
- 5:04 AM
- Sunset
- 6:42 PM
- Day length
- 13h 37m
Daylight overlap: 5h 37m — 11:34 AM–5:12 PM in Adelaide (5:04 AM–10:42 AM in Riyadh). Both locations are in daylight during this window.
Cities in these zones
Browse all cities to see the current local time anywhere.
Airports in these zones
Airports in Australian Central Time
- ADL
Airports in Arabia Standard Time
- JED
- RUH
- MED
- DMM
Related conversions
Common conversions
- What is 9:00 am Adelaide in Riyadh?
- 9:00 am Adelaide is 2:30 am Riyadh.
- What is 12:00 pm Adelaide in Riyadh?
- 12:00 pm Adelaide is 5:30 am Riyadh.
- What is 12:30 pm Adelaide in Riyadh?
- 12:30 pm Adelaide is 6:00 am Riyadh.
- What is 2:00 pm Adelaide in Riyadh?
- 2:00 pm Adelaide is 7:30 am Riyadh.
- What is 5:00 pm Adelaide in Riyadh?
- 5:00 pm Adelaide is 10:30 am Riyadh.
- What is 11:30 pm Adelaide in Riyadh?
- 11:30 pm Adelaide is 5:00 pm Riyadh.