Sprint 1 month includes the following events, too?

According to the Scrum Guide: 

A new Sprint starts immediately after the conclusion of the previous Sprint.

Sprints contain and consist of the Sprint Planning, Daily Scrums, the development work, the Sprint Review, and the Sprint Retrospective.

So all of the other events must take place within the one month timebox, and there is no time between Sprints, so every event can only take place during a Sprint.

Even though the maximum Sprint length is one month, the majority of teams I've encountered work with 2 week cycles. Each team should find its most effective cadence, and if one month feels too short, it's likely that there are other problems that the team or organization must solve in order to use Scrum effectively.

thank you Simon Mayer,

The Sprint itself is a container. All the events are in this container.

The Scrum team maintains a consistent pace of development activity through this fixed-time container.

All events are only set to the maximum time limit. For example, if Sprint Review can be completed in 2 hours, it will not take 4 hours. But the Sprint's length is constant. The rest of the time after the other events have been deducted is the time for development activities. 

Thank you Ching-Pei Li,

Based on your example, if the Sprint Review is  over in 2 hour ( instead of 4 hours ), then the Development team can use these 2 extra hours to make Refinement ( for ex ), as the Sprint is over, and there is not development activities for this current Sprint

Can they use it to start the Retrospective?

Sure, but not recommended.

Usually the scheduled time of the retrospective meeting should be decided beforehand.

The product owner can use the rest of the time with the development team to discuss goals or product items for the next Sprint. Or a Happy hour is also possible as the Sprint is over.