[otrs] Help: SQL to get all tickets closed in a timeframe?

We have an external reporting system tied into OTRS for running some agent reports, etc. I've been able to run some general queries on say New Tickets in This Week New Tickets Closed in the Same week However, I'd like an additional lookup to reflect the total number of tickets closed this week, regardless of when they were created. What do I need to query in order to get closed dates between Date1 and Date2? Charles