The Scheduler Hours/Costs are initially set when the schedule is published.
However, deletions or adjustments that occur after it is published can cause a discrepancy.
We highly recommend recalculating once a day or even once a week depending how often adjustments are made to maintain accuracy.
To recalculate costs on the Scheduler you will need to complete the following:
Options > Costs > Recalculate
(please see screenshot below)