To turn off auto-confirm for a certain date or for a few days, go to:
Click on the venue
Click on the relevant Booking Type
Scroll down to the 'Override dates' section
Click ADD ANOTHER and add the date or date range
Tick the 'can book' box, inputting your booking rules there as per your Availability (NB if you do not fill in the rules, Collins will override any rules already set up in Availability)
In the 'Auto-Confirm Max' column and input zero, this ensures you can take enquiries for the day(s) selected and that no auto-confirm bookings will come in
Make sure to SAVE the page.