If you are an organization that has offices spanning multiple time zones – then you have a dilemma. What time zone should you set for your SharePoint and how do you set time such that each user sees calendar entries and time stamps in SharePoint in their local time?
https://sharepointmaven.com/sharepoint-time-zone/
In this SharePoint Online tutorial, we will discuss SharePoint Online regional settings. How to change SharePoint Online regional settings for modern sites and classic sites.
https://www.spguides.com/sharepoint-online-regional-settings/