Issues where there seems to be a day wrong when handling dates are usually down to a mix of localized and non-localized DateTimes. Check your application and make sure the DateTime attributes you are using are consistent.
For more information on working with DateTimes in Mendix, have a look at the FAQ.
https://docs.mendix.com/refguide/datetime-handling-faq/
I hope this has helped. Good luck!
Add a change event to apply logic on end date before commit.