If you have DRM you can do a Q DRMSTATUS and it will show you.  You set
it by using the SET DRMDBBACKUPEXPIREDAYS command.

If you don't have DRM, it is controlled via the DELETE VOLHIST command.
 This was possibly set up as an administrative command that is
scheduled.  To check to see if it is scheduled as an administrative
command use the Q SCHEDULE * TYPE=ADMIN command.

Elvin