Lease Expiry Alert - Oracle Property Manager

We have a requirement of sending alert email based on lease expiry date in oracle property manager. Application should send an email 60 days prior to the lease expiry date.

I am aware about periodic and even alerts but not sure which one will use in this situation. I think periodic alert should be good but the frequency is the issue. We don’t want the alert to be send if no output is found by the query ie if I schedule the period alert on daily basis by keeping the condition of the query as lease expiry date-sysdate=60, the alert should send only if any data is found by the query.