Dynamic Dates In VBA

My spread sheet holds data with input dates recorded. Periodically there is a requirement to remove and copy elsewhere data that is older than 365 days using the Auto Filter. I have a macro that , on first pass, selects the required dates older than 365 days copies and pastes but on the 2nd execution of the macro with a different date required it doesn’t work. Looking at the code the date is not changed. Is there a way around this problem? I am also experiencing a problem finding the next available empty cell in which to copy. I have used serial numbers for dates having first had trouble with dates in dd/mm/yyyy format.