Hi All, According to technet the value should always 0 http://technet.microsoft.com/en-us/library/bb201689(v=exchg.80).aspx But I dont know why it always 2 in my envirnment Any ideas to troubleshooting??

Hello, You may check the application log to see if there are any free/busy related issues. Thanks, Simon

Hi Simon, Any Event ID? I can see some " An inconsistency was detected in Users: /Calendar. The calendar is being repaired. If a problem persists, please recreate the calendar or the containing mailbox. "