How can User change language and regional settings in SharePoint 365
To change language and regional settings in Offic 365 user need to flow steps
1 Login on Office 365 portal and Click on top right user profile icon and click on “MY Office profile”.
2 Click on “Update profile” button.
3 Under the Contact Information you can find Change language and regional settings. Click on the toggle button then ‘Click here’ link will appear for next steps.
4 Click on “…” then “Language and Region”.
5 Now you can change settings as you need and Click on “Save all and close” button.