Absence Management and 3rd party Time Entry

My organization uses the delivered functionality of Absence Management from PeopleSoft. We do not use the Time and Labor module of Peoplesoft. We use SAP as our time entry system for employees to enter their hours specifically towards different clients, projects, or time off. Does anyone else have a 3rd party system that they use for time entry? How do you compare or reconcile the leaves entered in PeopleSoft versus the time codes entered in another system?

We have found difficulty using the delivered module for the instance above. We have considered some customization, but so far any design we have come up with seems far too extensive to be effective.