AppInsight - Most Expensive Queries - for how long?

Hi

"Most Expensive Queries" in AppInsight for SQL, great thing! But for how long period of time is that?

Is it "most expensive queries for the last hour" as one might think as that is what you can filter on?

Would be great to have at least 24 hours so I can see what expensive queries that where ran during the night.

By the way: I think the text under the heading "AppInsight for SQL Alerts", page 411 in admin guide, is wrong...

Thanks!

/Thomas