Question:

What is the exact meaning of the term: Missed Schedule? 

Answer:

All Vaults are put into maintenance mode while deploying General releases to customers. Jobs are not run during that scheduled downtime. If a Vault is in maintenance mode for 6 hours following a job's scheduled time to run, the job status is marked as Missed Schedule and proceeds to run as scheduled the following day.

Related Documentation:

Vault Help Documentation: Vault Help