Under the middle button, at All, is Calendar: everything that’s planned and everything you’ve done, in one place.
The month view. At the top you see the month as a grid. A day with a dot under it has something on; more dots mean more appointments. That way you see the shape of your month -- where the gaps are and where it gets busy.
The day below. Tap a day and you see what’s on that day, with the time. Completed workouts are crossed out, so you can see at a glance what’s still to do.
What’s in it. Workouts from your coach’s plan, your own sessions, booked group classes and your outdoor runs. All together and not in separate lists.
Adding something yourself. The plus at the top right lets you add something that doesn’t come from a plan.
The week starts when you want. Monday by default; under Profile → Personalise you can change it to Sunday.