「シャワーの時間はどれくらいにした方がいいですか？」って英語でなんて言うの？

"Is there a certain time I'm allowed in the shower?" Here you are politely asking if you can use the shower and asking for how long. The hosts will then politely reply and tell you the length of time you will be allowed to have a shower. Hope this helped :)

Rules are a list of dos and don'ts which will tell you what you should keep in mind as you are in the shower.

Explanation: If something such as an activity, game or procedure must be completed within a fixed period of time, then you describe this as the 'time limit.' Example sentence: 'The time limit for completing all your answers is 30 minutes."

These are all polite questions using "please" and on their reply you would answer with a "thank you". I would also ask what time is best to have a shower, in some places they only have hot water available at certain times or the water takes time to re-heat after the last person has used it. By also asking what time is best, it is being polite in understanding that other members of the household also have a routine and you would need to fit in with. It is also polite to not "hog" (stay in the shower for hours), when others need to use it.

The suggestion above is quite polite and comfortable, by asking what your host recommends. If you ask for a time limit or a rule about showering, they are likely to be surprised or flustered as a shower is a personal action and they wouldn't want to dictate a set rule to you. Note that you will probably take longer showers if you are shampooing or shaving your legs or are very dirty than otherwise.