The effective date of a document is a day behind when the job is run.
The Time zone is set differently in Vault than it is in the Loader job.
Date discrepancies can appear in audit logs if the Vault Loader time does not match the default Vault time zone.
Example: A Vault time setting is set to Eastern Standard Time, and the job is scheduled to run in Vault Loader at 12:05 GMT on the 16th. Using conversion to time zones, the effective date appears as the 15th. The job takes place at the intended time (at 12:05 GMT). Vault automatically converts the time to Eastern Standard Time in the logs.
Vault Help Documentation: Vault Time Zone