If you need to stop sales for a particular ticket type (i.e. Early Bird ticket) or set sales to stop at a specified date and time you can do so by editing the ticket type.
Stop sales for a single date
From your Event Home, go to the Details tab.
If your event has more than one date and time you need to select the date and time that you're stopping sales for. To do that click on the dropdown arrow next to currently selected date and time and select the date and time you'll be stopping sales for.
Once you're on the single date you want to stop sales for or if your event only has one date, under the Sales drop down menu, select the Stopped option.
If you'd like to turn your sales back on, simply change the sales status back to Active.
If your event has multiple dates and you need to stop ticket sales for all dates, click Advanced Event Settings under the event's Details tab and scroll down to Start/Stop Sales. Then click Stop Sales For All Dates.
You will see in your Dashboard that Sales are Stopped on All Dates.
If you need to restart sales, click Start Sales For All Dates.