Expiry date for the application pushed through MDM

Hi I am pushing an IPA through MDM. Thought the distribution certificate's expiry date is June 2019, the expiry date visible in the MDM is 1st November 2017. I have the following questions: • On what basis is the expiry date of the application is set? • From where does the MDM pick the expiry date? • Is it possible to set an expiry date manually? • Is there a way to Auto-renew the date to save us the effort of re-creating the build? Thanks