Date Setting Format - Need dd/mm/yyyy

Date Setting Format - Need dd/mm/yyyy

Hi, I have changed the date in the main settings to the UK format (dd/mm/yyyy) but it still shows up in the American format (mm/dd/yyyy) on most of the system, for example in schedule and event, date details inputted to Zoho Recruit etc... please can you tell how I can change this as it is very annoying. Many thanks, Alyson