Skip a Habit or Smart 1:1 from the Planner calendar
Right-click the event from the Planner Calendar
Select Skip.
Click Confirm (for Smart 1:1s).
Skip a Habit or Smart 1:1 from the Planner side-panel
Click on the Habit or Smart 1:1 from your Planner Calendar to open up the details in the side panel.
Click the three dots labeled More options next to the Habit or Smart 1:1 instance.
Click Skip.
Click Confirm.