Sandbox: canceling PENDING subscription schedules cancellation one day after future start

Questions
1
  1. Subscription ID: a45bdfae-a7eb-4941-ab24-82c784641689
  2. Timezone: America/Chicago
  3. Future start: November 18, 2026
  4. Cancellation requested: October 17, while PENDING
  5. CancelSubscription returned cancellation date November 19
  6. No invoices or charged_through_date

Will this subscription charge on November 18? What supported operation cancels it before its first charge, and could this relate to the sandbox date issue acknowledged in my linked thread Sandbox subscription returns November 3 for requested November 2 start) ?

3

Unfortunately we do not have full sandbox support for subscriptions. Sandbox can be used to validate Subscriptions API request/response shapes and some subscription object behavior, but it does not reliably exercise the full end-to-end subscription lifecycle.

5

Thank you for clarifying the sandbox limitation. For production, what supported API operation cancels a future-dated PENDING subscription before its first invoice or charge? Does CancelSubscription guarantee this when called before start_date? If sandbox cannot validate that behavior, what verification procedure does Square recommend before release?