As the attendee or organizer of a Smart 1:1, you can always opt to skip a 1:1 for the period and it won't be scheduled until the next interval. There are two ways to skip a Smart 1:1.
Skipping via Reclaim
From Smart 1:1s page, find and click on the Smart 1:1 to enter into its details page.
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You can also skip a 1:1 via the Planner by right-clicking on the 1:1 event and selecting the Skip option:
Skip a Smart 1:1 from the Google Calendar
As the organizer or the attendee, click the Skip link within the event's description. If you're the organizer, you can also just delete the event.