How do I make sure the client is booked for today's session?

When your client books they will receive a booking confirmation email showing the date and time they have booked for. Unless you have disabled QR code links, there will also be a link to a QR code next to each date they are booked on.

If they show you that QR code page it will tell you which date/time they are booked on and it will show if that is today or not.

This is useful to make sure the client hasn't accidentally turned up to the wrong session.

And if you scan the QR code with your phone camera it will take you to a page where you can double check the date and mark them as attended with the click of one button.

So as well as streamlining attendance tracking these QR codes are also like the clients' "tickets" and will help you make sure someone has come to the correct session.

If you don't want to use QR codes, or have them disabled, just ask to see the customer's booking confirmation email, or take their name and check in your bookings panel that they are booked onto today's class. You can mark them attended there also.