List of new Errata available from specific date

Hello everyone,

I have a Content View that contains the official repositories from Red Hat.

From time to time (every 3 months) I need to generated a CSV file with the NEW (only new) errata available from specific date.

Example:
Month 1 - Day X: I generate a CSV file with a list of all erratas available on the content view using the command "hammer --csv --csv-reparator ";" erratum list --content-view ID"

Month 4 - Day Y: I need now to generate a similar CSV file list but ONLY with the new errata list available from Day X.

Is this possible? Maybe I need to create a filter on the content view. Anyone can help me how to create this report properly?

Thanks in advance.