RMAN "delete noprompt obsolete" by date?

I am at a new company and I have discovered that the "delete noprompt obsolete" command has not been executed.

As a result, the database control file is immense and the list backup summary takes almost 10 minutes to execute.

It would take too long to execute the delete expired backups "delete noprompt obsolete" command.

(Q) How can I delete obsolete backups by date?

That way I can break the delete operations up into smaller groups and not affect system performance or normal backup operations.

There are just too many to delete one by one.

As you can see below, I have backup information back to 27-DEC-06