Timeboxing is the practice of ending a meeting exactly on time regardless of the state of discussion or the desire of participants. In Scrum, the combined length of the Sprint Review and Retrospective Meetings is determined by the length of the Sprint. For example, a one week long Sprint has Sprint Review and Retrospective Meetings that are timeboxed to two hours in total. It is acceptable for the meetings to take less time, but not more. A two week long Sprint has a Sprint Planning Meeting that is timeboxed to four hours. Keeping the Sprint Review and Retrospective Meetings timeboxed has two beneficial effects: one, the team keeps the overhead dedicated to meetings to a relatively low level, and two, the team learns to do effective inspect and adapt in a very short period of time. If the meetings are not timeboxed, then typically the team will keep going until they are “done”… and break the timebox of the overall Sprint.