If your event has tickets that aren't onsale yet you can add the ticket link and ticket type and toggle On-Sale Notification On. Then you can add the On-Sale date and time. The time zone is the time zone of the venue.
The Notify Me button will display until the On-Sale date and time has passed. Users who click this button will be alerted via email and notification that tickets are onsale on the On-Sale Date. If you want the ticket link to display before the On-Sale date you can change the ticket type from Tickets to Presale and the ticket link will display immediately. You can also remove the On-Sale date if you prefer.