XF 2.2 "Activity summary" email trigger / how often?

[goforyourdreams]

I enabled the "Activity summary" email several hours ago (to be sent to users inactive for 2 days) but so far nothing has been sent (the test e-mail was sent fine). What triggers this email and how often?

 

[Chromaniac]

admin.php?cron/activitySummaryEmail/edit

there is a cron entry for it.

Tools > Cron Entries > Send activity summary email