When an imported case fails to find a date for the opinion cluster, it takes date_modified from docket for the month and day.

This occurs for the Columbia corpus. It is unknown whether it affects previous imports.

Mike Lissner:
I think I know where this bug comes from. I think date_util does this if it doesn't know some part of a date. I think I had it set up with December 25th as the default when I did some of the early imports and it would throw an error if any case was on that date.

Options:

1. Re-do the import with better code.
2. Do a query looking for cases where docket.date_modified==cluster.date_filed (just for month and day). This would have a lot of false positives.
3. Resolve many of these as part of a larger audit of case chronologies based on the reporter page numbers.