After an import that inserted instead of updating, there was no way to
ask which records it created: an import of old contacts carries old QSO
dates, so it hides among them. created_at is the only column that knows,
and it was not filterable.
Listed as a date column so a bare YYYY-MM-DD compares on the date part,
like qso_date.
rouggy
20784c2fb1