Hi Chentor and Drew, thank you for the suggestions. The main server is down for maintenance and when it is up again, I will try both ways for efficiency and...

Hi Chenthor, I have tried your query and it returned the "previous 1 row" when the hourly was changed, but not the minimum date that I am trying to get...

Thanks for the replies.

John, I have tried that but it did not get to the results I wanted because the LAG function did not go back far enough...