[UX] Clarify Field Type choices on Field Settings page

I think most non-developer users are pretty perplexed when faced with the Date choices presented to them while adding a date field to a content type.

I am not sure what would be the best way to address this issue, but here are my thoughts so far.

• There is a need for a short description somewhere near where the user has to make this choice and due to the complexity of the Date formats possibly also a link to more detailed documentation.
• There is not enough space on the Manage Fields page at /admin/structure/types/manage/foo/fields for brief explanation or even a link.

One option could be to present the user only with one choice and then allow them to select one of the Date formats on the Field Settings page where there is more space to provide some brief description next to each Date type with a link to more detailed explanation.

Can anyone think of a better (easier or more user friendly) way to present this choice to the user?