AchievementDateFormatter (1.1)

This addon changes the formatting of dates from the United States English format of “M/D/YYYY” (Month, Day, Year) with no 0-padding on the month and day to another format of your choosing.

The addon’s menu allows you to pick your own date format such as DDMMYYYY or YYYYMMDD with a list of separators like / – . (space) etc. If these do not suit your requirements, select your own custom separator.

This addon will only work properly on the English client as the input date format on other clients is different.
If there is any demand for accommodation to other clients I may update this in the future.