Adding Cultures after Go-Live

Lastly, you need to review your application to see if there are any assumptions on Date Formats.
This is especially true if your application is using a Specialty Mktplace solution (e.g. People Planning) and you need to retrieve dates from a register table, or any other relational table in your application.
I've lost count the number of applications where there was an assumption that dates would be retrieved and interpreted as US date format (mm/dd/yyyy) and I've even seen people hard-code assumptions into the way their rules break up these date strings into components.   The best application is one where you never use strings to represent dates.