I'm pretty sure this is a bug in FileMaker Pro/Advanced 12 and have submitted a support ticket, but wanted to see if others are seeing this.
Create a new database with one table and one date field.
Create a new list with the date field on it.
Format the date field to use a value list using values from itself.
Create some records and insert some randoms dates.
The dates in the date field are formatted as dd/mm/yyyy (UK system) but the value list shows them formatted as mm/dd/yyyy.
I have changed system formats, played with other things but nothing I do has any affect or resolves this.
I have verified it on other computers I have here and am seeing the same thing.
Hoping others are seeing it too?!