Dear User,
Thank you for raising the concern.
The 'Start-Date' and 'End-Dates' options on 'Create New Entitlement' page is to specify the calendar dates within which we can perform operations related to the current entitlement, such as activating its product keys.
More details are available in product documentation 'Sentinel LDK-EMS User Guide'.
Please feel free to share your further queries.
Best Regards,
Parth Kaushik