Thanks for taking the time to respond, really appreciate it. Options 1 and 2 aren't suitable. How would I filter the data using a calculated dimension? Giving a bit more detail, I have a table containing an ID number, the date it was added to the database and the time difference between the date added and now.
What I want to do is only show rows where the difference in seconds is greater than 540,000. I have a calculated expression called 'M_Seconds' that contains this value for each row, but if I do IF(now - logdate > 540000, now - logdate) on the expression then it doesn't actually filter anything out.