Once a session has been created, you will need to apply one or more Timetable Weeks to the physical calendar weeks in the Session's date range.
The session page will display a calendar of months for the whole session.
Click on any date in each week to cycle through the weeks and apply it to that calendar week.
If you need to un-apply a timetable week, keep clicking the date until the colour and label disappear, leaving an empty background.
When you've finished applying the weeks to the whole session, click Save at the end of the page.
You can use the Bulk apply section to apply the selected timetable week to every week in the session's calendar in one go. This is useful if you run a simple one-week timetable.