Check Conflict in ics Location - dday.ical

Hello 
     I have a web form that user use to create new event , but in the admin page before approving the event the admin need to check the location/date has any conflicts even in the recurring event. I have to show and stop the admin approve process if there is any conflivcts even in recurring event..
I'm storing my data like this and using dday.ical
any suggestions appreciated.. Thank you
ConferenceTable 
      [ConferenceID] ,[ConferenceType] ,[ConferenceName] ,[Purpose] ,[ConferenceStartDate] ,[ConferenceEndDate] ,[StartTime] ,[EndTime] ,[RRULE] ,[Category] ,[Status]
            45                       video             testname                             &nbs ...