Currently when you create a DateTime attribute for an entity the setting 'Localize' is set to 'Yes'. I think it is better to set it to 'No' by default:
In my experience many people (that start with Mendix) don't know the impact of this localization and get boggled by the fact that when let's say they select a date in a datapicker "01-Jan-2017" the value in the database gets stored as "31-Dec-2016 - 23:00".
Figuring out why this happens takes a lot of time and it would save a lot of frustration to just set this property to 'No' by default and set it to 'Yes' when you actually need it.
I would suggest to instead create project settings for these kind of default values. So that your prefered default is automatically applied to the entire project.