Fix the Regional Settings mess
A lot of people are having issues with Excel Online regional settings, whether it comes to dates or formulas language.
(just a few examples)
Changing the locale of a spreadsheet shouldn't be something so complex that we need to post for help on a forum (to eventually get no answer anyway).
In Google Sheets it goes like Files > Spreadsheet Settings > Language, and that's how simple, straightforward, intuitive and clear it should be. No settings that comes from other settings in another part of the maze of apps from Office 365.
Tharindu Gurusinghe commented
Please add a option to change the language settings in Excel online. Cz I'm living in Italy but I'm using the English as the Default language. But in Excel it is giving Italy formula tags instead of the English and it is totally a mess. Please resolve it.