ezdatetime issues:

When contentobject attribute is ezdatetime type and is set as "IS NULL" in database (this can happen when you adding new attribute to content class which already has some objects) package manager will produce code like:

            <ezobject:attribute ezremote:id="767"
                                ezremote:identifier="unpublish_date"
                                name="Unpublish date"
                                type="ezdatetime">
            </ezobject:attribute>

in contentobjects.xml

Missing is <date_time>Thu, 01 Jan 1970 00:00:00 GMT</date_time> tag so produces warning in kernel/classes/datatypes/ezdatetime/ezdatetimetype.php line 571

System should set data_int=0 in database for contentobjects that already exists in database when new ezdatetime attribute was added to class definition.

Import:

Dates are not imported from ezdatetime attribute defined in contentobjects.xml

            <ezobject:attribute ezremote:id="939"
                                ezremote:identifier="publication_date"
                                name="Publication date"
                                type="ezdatetime">
              <date_time>Mon, 26 Feb 2007 07:03:00 GMT</date_time>
            </ezobject:attribute>

In database data_int for ezdatetime attribute is NULL, however date is correct in contentobject package.