The easiest way is probably to setup a sqlite db with at least one issue class which has a date. Add a few issues and add a bunch of responses to the issue(s) to cause some records to be written into the journal and then export it.

Then try to reimport it (not sure if the db type matters). That's when it occurred for me (well during a migration from sqlite to mysql). The dates written into the exported datafile will look like python class instances <Date
2007-10-12....> which can't be imported.