>When I schedule a backup, it works but the backup is always launched 10
>minutes after the time I wanted. During those 10 minutes, the status of
>my schedule is "Pending", and after it becomes "Started".

Schedules involve a "startup window".  They do not necessarily start at
the leading edge of that window.  See Randomizing Schedule Start Times
in the Admin Guide.

  Richard Sims, BU