Dear,
In general, MRP results are not stored in MDTB, due to the performance of the system. This is done in OPPQ -> Performance -> Aggregation of MRP List -> Transp. MRP check-box. With this activated, MRP list is stored in MDTB. Otherwise the results are there in MDTC in an aggregated format.
To get the rescheduling date, used function modules like MD_STOCK_REQUIREMENTS_LIST_API (for MD04 data), or MD_MRP_LIST_API for (MD05 data).
From the export tables, you will get the UMDAT value.
I would suggest MDEZX-UMDAT.
Best Regards,
Rajen