Hi there! We use the locality provided to us by the browser you're using to determine the "local" date formatting, which is in turn provided by your operating system. More information on this can be found here.
If your operating system is showing the right place, you can also check the browser locale by typing navigator.language in your browser console window. If you're seeing American date formatting, you might have this set to en-US.
Additionally, if you're using Chrome, for example, you can also set this by navigating to chrome://settings/languages#lang and setting the language to the proper region. Make sure that this option is also set to the top of the list after setting it. Once you do so, Airtable should then set your local date format to DD/MM/YYYY.
If possible, as a quicker solution, you might want to modify the date formatting to European if you'd like to display DD/MM/YYYY formatting without modifying any underlying settings. Hoping this can help!