Date formats in IPS 4 can be formatted and translated by changing language strings to any format you wish to show them in. You can find date related strings prefixed with _date within your language pack.
If you are unsure on how to manually translate language strings, you will need to read the following guide first of all
Language strings are made up of separate elements relating to the day, month, and year. In this example I will be editing the language string _date_last_year_long .