List the dates of enrollment and completion of the student with family name "Zieme" and personal name "Bernie".
return students ;return family names of  #1 ;return #1 where  #2 is Zieme ;return personal names of  #1 ;return #1 where  #4 is Bernie ;return #1 of  both #3 and #5 ;return date of  enrollment of #6 ;return date of  completion of #6 ;return #7 ,  #8
['select', 'project', 'comparative', 'project', 'comparative', 'intersection', 'project', 'project', 'union']