Some people asked me about Sprint Length and how to define sprint length. Most of the concern is can we do Scrum with 1 day Sprint? Can we do Scrum with Sprint longer than 1 month? So this post will go through this topic.
1-day Sprint

Yes, you can do Scrum with 1 day Sprint. But you need to take into account how all events be held in one day? And does development team have enough time to deliver working software? Some experiences showed that, if Scrum length is less than a week, the team will have tendency lead to removing all events to focus to develop features.
Remember that Scrum based Transparency, inspection, and adaption. If team use time to build working software but lack of formal opportunity of inspecting and adapting, they will lose the chance to learn and improve.

So If your business really must have working software release every day, you can do 1-day sprint, but that not is a recommendation.

Sprint longer one month

Sprint's time-box is one month, but Scrum does not stop you to have Sprint longer than one month. If you want to do sprint longer than one month, you need to consider: it will reduce focus, increase complexity & risk, valuable of feedbacks can be lost from stakeholders and market. Of-course, It's not Scrum.

How to define Sprint length?

You can use some indicators below to define Sprint length:

- Market changes: How your market conditions and how fast it changes?
- Level of Team's maturity.
- The uncertainty of technology.
- How long to have feedbacks from stakeholders to make sure team build right value first. (if product knowledge is low, PO doesn't know what is the right value of the product -> In this case, the solution is: deliver fastly and learn from the market is top priority)
- Dependency on externals.
Remember Scrum doesn't say you only can release working software by end of Sprint. So at any time Done increment is ready, you can deliver it anytime and many times in sprint.

Last but not least: Remember, Rhythm is important to help the team learn and improve, follow with this product value also increase. So, keep your Sprint length stable and have Scrum team to define it at the beginning is important. Read more about Rhythm at Start Scrum team with Rhythm