Change Office 365 Language
You can also change the preferred language per user. Click on the user avatar in the upper right corner, select View Account, then settings from left column (last icon).But I tried this to see what happens in OneNote. No impact. The timestamp remains in original language (in my case, English). I signed out of Office 365, then signed in again. Now all the tools in OneNote are in Spanish, but the timestamp on a new page is still in English. I didn't change my organization language, so if both org and user language are set to French? English?, then sign out and sign in again.
It may take 24 hrs for a global tenant change to take effect.I did a bit of research and found that, at least for default font information, OneNote uses whatever your settings are in desktop OneNote. If you have desktop OneNote, verify the default proofing language is correct. Since notebooks are automatically synced, it affects OneNote Online also.
Set language and time zone for multiple users from CSV: Use the below powershell commands to set regional settings for bulk office 365 mailbox users by importing users from CSV file. Consider the CSV file MailBoxUsers.csv which contains set of mailbox users with the csv column headers UserPrincipalName, TimeZone, Language, DateFormat and TimeFormat. Change your display language and time zone in Office 365 for Business Sign in to Office 365 with your work or school account. On the top navigation bar, click Settings to open the Settings pane, then click Language and time zone. Under Language and time zone, select your language from the list. To do this, I went to My Account on office.com, and clicked Install. An installer downloaded and ran. There were no options and I paid no attention, it just did its stuff. When I run Office, it is now using Estonian. To be clear: The older installation of Office 365, Office 2013, used English. My Windows language settings (Windows 10) are English.
Change Office 365 Language Settings
Apps you use in Office (such as Outlook, Word, Excel, PowerPoint, and OneNote) include a proofing feature to edit spelling errors and check grammar to ensure that you can create email and documents as clearly and as effectively as possible.