How can you auto-refresh a SharePoint 2010 calendar list / web part, without needing to refresh the whole page? Tasks and other list types seem to have this option (under 'AJAX Options'), but not calendars.
modify master page and add Java-script simple code to that refresh it every N seconds.
you can search with Google and using those JS codes.
this is helpful for those pages that contains these web parts >> like charts and calendar and etc. that we haven't those options.
after this answer i search here in this stack and found similar question and answer:
I would recommend using content web part instead of modifying master page to store JS. But in other steps I agree with "saber tabatabaee yazdi".