Below is a list of restrictions and limitations that apply to garage sales in the Blacktown Council area. What you can see is pretty much a copy and paste of the information that was provided to me by the Blacktown Council. I suggest you use this information as a rough guide only and double check to be sure.
Garage sales are permitted in accordance with Item 25 of the Exempt and Complying Development Summary (see excerpt below), i.e. maximum of 2 per year, on residential land, during daylight hours and a maximum of 2 days per sale.
The rules on this website may be outdated or wrong. It is your own responsibility to make sure that you adhere to the current rules and regulations that apply to garage sales in your area.