How does one Determine Number of Total Hours in a Work Schedule Using Time Calculation Rule

Summary: The requirement is that part time staff may work overtime, but receive regular rate and not overtime rate until they have worked up to 35 hours. They only record overtime in OTL, not their regular scheduled work time. When I retrieve the work schedule, it is for the day that overtime is recorded, and I cannot look at it for the full week. This is giving erroneous result.

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The employee works 25 hours a week, but does overtime on 3 days of 5 hours a day. That would result in Regular Hours of 10 and 5 hours of overtime worked outside of their scheduled time. With the schedule DBI, I receive 5 hours work schedule and can compare against 7 hours daily work, which would mean deducting 2 hours to make 7 full time hours and 3 overtime hours for the day. The problem is that the employee has not worked 35 hours yet, so there should not be overtime at 1.5 rate.