Australia DST (AEDT) — How AEST/AEDT Changes the IST Gap
Australia's south-eastern states — New South Wales (Sydney), Victoria (Melbourne), Tasmania, and the ACT — observe Daylight Saving Time. Crucially, Australia's summer is October–April, which is opposite to the Northern Hemisphere. This means when US and UK clocks fall back (November), Australian clocks are springing forward — making scheduling complexity peak in those weeks.
Clock Change Schedule
Clocks spring forward 1 hour on the **1st Sunday of October** at 2 AM (AEST→AEDT) — marking the start of Australian summer. They fall back on the **1st Sunday of April** at 3 AM (AEDT→AEST). AEDT is in effect from early October to early April — Australia's summer.
| Spring forward (AEST to AEDT) | 5 October 2025 |
| Fall back (AEDT to AEST) | 6 April 2025 |
| Spring forward (AEST to AEDT) | 4 October 2026 |
| Fall back (AEDT to AEST) | 5 April 2026 |
Australia (South-East) Cities — IST Time Difference
How the IST gap changes for each Australia (South-East) city between standard and DST
| City | Time Zone | IST gap (AEST / standard) | IST gap (AEDT / summer) |
|---|---|---|---|
| Sydney | AEST/AEDT | 4h 30m ahead | 5h 30m ahead |
| Melbourne | AEST/AEDT (Victoria) | 4h 30m ahead | 5h 30m ahead |
| Canberra | AEST/AEDT (ACT) | 4h 30m ahead | 5h 30m ahead |
| Brisbane | AEST only (Queensland — no DST) | 4h 30m ahead | 4h 30m ahead (no change) |
| Adelaide | ACST/ACDT (UTC+9:30/+10:30) | 4h ahead | 5h ahead |
| Perth | AWST (UTC+8, no DST) | 2h 30m ahead | 2h 30m ahead (no change) |
IST to AEST/AEDT Quick Reference
Both standard (AEST) and summer (AEDT) conversions at a glance
| IST (India) | AEST (standard, winter) | AEDT (summer) |
|---|---|---|
| 12:00 AM (midnight) | 4:30 AM (same day) | 5:30 AM (same day) |
| 6:00 AM | 10:30 AM | 11:30 AM |
| 9:00 AM | 1:30 PM | 2:30 PM |
| 12:00 PM | 4:30 PM | 5:30 PM |
| 3:00 PM | 7:30 PM | 8:30 PM |
| 6:00 PM | 10:30 PM | 11:30 PM |