Sunday
The police have reported that 1.4 million vehicles entered the ACT (Australian Capital Territory = Canberra) on the Friday before the protest. Guessing an average of at least 2 people per vehicle (I witnessed many with 4 or more), that is almost 3million people.
Bear in mind that no one wants to go to Canberra, the capital of Australia, without good reason. It is infested with politicians and public servants.