There ought to be a way to set up one and only one date format for a projects. Once this has been set this date format should be enforced by Revit anywhere where a date is entered. Dates should be entered via a date picker and not as free form text.
Optionally, Revit could offer the users to set up a number of date formats and let the user choose which format to use when entering dates. Default format should be used as the initial choice.
This would be very helpful in many cases. Revision schedules and revisions on sheets is just one example.
Letting people type in dates as free form text is inviting errors and frustration. Humans are just not very good at formatting stuff 😉