What is the maximum time-box allowed between the conclusion of the current Sprint and the next Sprint?

The maximum time-box allowed between the conclusion of the current Sprint and the next Sprint is none. In Scrum, the continuity of Sprints is emphasized to maintain a consistent rhythm and ensure that the team is always working towards delivering increments of value. As soon as a Sprint ends, the next Sprint should begin, which fosters momentum and minimizes the gap between periods of productive work.

A core principle of Scrum is the concept of time-boxing, which ensures that all events are to occur at fixed intervals. The only time that might necessitate a break is during a Sprint Review or Retrospective, but those should not cause substantial delays in starting the next Sprint. Maintaining this continuous cycle minimizes the risk of losing focus and helps the team stay aligned with delivering increments regularly.

The other options imply interruptions or variations in the Sprint schedule that go against this principle of continuity. For instance, enough time to release the increment or for debugging could unnecessarily lengthen the period between Sprints. A maximum of one day for two-week Sprints is also too specific and does not reflect the Agile tenet of flexibility in timing.