Hi, Jon.
The date format controls can be found at Tools>Options>Themes&Formatting>Date&TimeFormat>General
The documentation of the available formats can be found in the users manual starting at the bottom of page 117. Check out the formats “r” or “R” (for Relative). The rules for switching format when the date gets close are on
Tools>Options>Themes&Formatting>Date&TimeFormat>Advanced
However, I don’t see any options for formatting based on the interval between the date being formatted and the due date, it’s always the interval between the date being formatted and today.
-Dwight