Regional format settings in Excel affect dates, currency, formula delimiters and more. If you are using your organization account, the default regional format settings in Excel for the web are the site regional settings of the SharePoint site where the Excel workbook is hosted.
This article provides steps to change just your own regional format settings in Excel for the web. During your Excel for the web sessions, the SharePoint site regional settings will be overridden. Your preferences are stored using a third-party cookie. Your regional settings will only apply to your view of Excel workbooks – it will not affect how other people view these workbooks.
If your third-party cookies in the browser are disabled, you will not be able to change the regional format settings this way.
This feature is only available for files stored on Microsoft hosts.
Set the preferred regional format in Excel for the web
Click File > Options > Regional Format Settings.
Click the regions drop-down, select a region, and then click Change.
Your browser session refreshes using the new setting.
Regional format can also be set from the Number Format dialog.
Click Home > Number Format > More number formats...
Under Category, click Date, Time, or Special, and then select a locale from the Locale menu.
Select the checkbox to set the chosen locale as your default regional format, and then click OK.
Your browser session refreshes and uses the new setting.