Why should I change the date range or interval?
It can actually be a bit dangerous to focus too much on the day to day happenings of your business. Sure, it's important to keep an eye on things, but you shouldn't radically alter strategies based on a couple of bad days of churn.
Looking at your data in the long run can help to see if it's trending in the right direction.
Combine a long date range with trend lines to better understand the story your data is trying to tell you.