The date settings may display with the month before the day (mm/dd/yy) in Office 365. To resolve this issue, please follow the steps below.
1. Go to the Staff iD page and select the 'One Drive' link in the top left of the screen;
2. Log in with your firstname.lastname@example.org account, then click the settings (cog) icon;
3. Select Site settings;
4. Select the
Regional Settings link under Site Administration;
5. Set the Locale to 'English (United Kingdom)' and ensure the Time Zone is set to UTC Dublin,Edinburgh, London.