ASX normal trading hours are from 10:00 am to 4:00 pm Sydney time on business days. However, there is an opening phase that starts slightly earlier and a closing process that includes an auction window:

• Opening phase: The market begins with an opening calculation and price discovery around 9:59:45 am Sydney time. This is a randomized short window before 10:00 am, after which normal trading begins.
• Normal trading: 10:00 am to 4:00 pm Sydney time.
• Closing process: There is a closing auction around 4:00 pm, with a brief period (roughly 4:00–4:10 pm) where orders can still be entered or amended, depending on the platform and product.

Notes:

• Some sources describe staggered or alphabetically staged opening times for individual stock codes, but the mainstream cash market is generally considered to open at 10:00 am and close at 4:00 pm Sydney time, with an opening calculation just before 10:00 am and a closing/auction window at the end of the trading day.
• If you need precise daily timings for a specific ASX product (e.g., cash market vs. derivatives, or during holidays), or want the exact opening times for today’s date, I can pull the official schedule for the current trading day and any holidays.