Data for Microsoft Lists is stored in OneDrive. Date setting in Microsoft Lists inherits from the OneDrive.
To change the date format of your Microsoft Lists, go to OneDrive settings.
1. Open your browser and login to OneDrive https://competenz-my.sharepoint.com/ using your <username>@competenz.org.nz and password, click Settings icon
2. From the upper-left section of your page, select More Settings -> Regional settings
3. Under Region, change the Locale to English (New Zealand) and click OK to save
https://competenz.freshservice.com/support/solutions/articles/5000083005