Plan procurements - Baseline Schedule vs Project Schedule

Hello, I noticed that in Plan Procurement, we use the "project schedule" as input, rather than the "schedule baseline". As I understand, the difference between the "project schedule" and the "schedule baseline" is that when we update the schedule baseline, we end up with the project schedule. At the start, both of them are the same, but once we start reflecting the progress on the baseline we get the project schedule, which will illustrate the deviations.These deviations need assessments, and if we can sort them within the project limits (by schedule compression, corrective actions,...) without changing the project end date, scope, contractual milestone, cost performance baseline, funidng requirements, ...; the project manager takes the decision. Otherwise, the project manager will seek approval for the change requests, corrective actions,... Now, when we prepare a Contract, I deduce that we have to use the project schedule, not the schedule baseline, in order to reflect the real project situation. For example: the schedule baseline has 31 Dec 2011 as end date for the project. The project schedule reflects the project will end on 31 Jan 2012. Attempts for schedule compression reflects the project will not finish earlier than 20 Jan 2012. The project manager seeks approval to extend the project till 20 Jan 2012. In parallel to this, IFB is under preparation. Which completion date shall we include in the IFB for a seller whose services are the last activity in the project? (considering lessons learned are done while we are closing the procurement for this seller). Thanks and best regards, Sherif