Click on "Timetables" on the left menu and then on "New".
Enter a name, choose a Time mode : 24h mode or 12h mode (with am/pm) and select "Fixed" type (selected by default), then choose a Start time
Define a number of columns (The number of days for example), choose if you want to displaythe title and activities filters and enter column names (day names for example). Columns heading are managed by the Joomla! Tags component. See how to manage Tags here.
Choose a background color for empty cells. Select the access group and the status.
Enter a description with image, links etc. if you need.
Define Timetable permissions (Delete, edit, edit status and edit own) if you need. See how to manage permissions here. Click on "Save" to generate the timetable and wait the page reloads.
The timetable is generated. A new page and a new tab "Timetable" are now displayed. See how to manage the Timetable and insert or create new activities.