If you are newer to timed ticketing and wondering how exactly to set your capacity or what times of day are busier for you there are a few things to know to help you track this.
First, if you are scanning you will get the actual attendance compared to capacity. When you scan a ticket the system marks this ticket as attended.
To track attendance you can scan your online ticket purchases at entrance. We know some of our organizations are mounting their scanners for touchless scanning and scanning directly from devices so that tickets don't have to be printed. There are community posts about these options.
For walk-up purchases you need to be sure that the Ticket Scanning Options are set correctly. You can find these in Tickets, Configuration, Ticket Scanning Options. Here you can set Tickets sold through Daily sales page on the day of the event count as scanned: Once the ticket is sold. As you see here:

Then, for reporting % to Capacity and tracking this to determine your capacity settings moving forward you can find great options in Altru's standard reports. I like the Average Hourly Sales report, Event Attendance Detail Report and my new favorite for this, the Ticket Availability Report. You can filter these by program or date. Here's a view of the Ticket Availability Report filtered for my daily admission timed ticketing event:

If someone purchases tickets online for a timeslot but then shows up later you should reschedule the tickets (search based on order number) into the new time slot. Then scan. The ticket number remains the same even if the time changes so that will still work!
We know that timed ticketing is a bit new for some organizations. As you track capacity and learn more about how best to manage that I hope these reports help!