To configure reminders for specific Activity Type:

1.  Go to *Settings \> Technical \> Activity Types*
2.  Open a specific activity type
3.  Fill *Reminders* field with a non-digit-separated list of offsets
    (in days) when reminders should be fired: e.g. 0 means "on the
    deadline day" while 5 means "5 calendar days before the deadline".