• I also find the schedules you mention very odd.

    A rather common frequency is:

    FULL: weekly

    DIFF: daily

    LOG: every 30 mins

    But the frequency really depends on your business requirements. How much data loss is acceptable and how much time you get to get back in case of disaster.

    ** Don't mistake the ‘stupidity of the crowd’ for the ‘wisdom of the group’! **