<i>I graduated last February 2010.<br/></i><br/><i>I graduated last February.</i><br/><i>I graduated last February 28.</i><br/><i>I graduated last February of this year.</i><br/><br/>I know that the prepositions 'in' and 'on' are more common in the sentences above, but is it also acceptable to use the word <b>'last'</b>?<br/><br/>My friend says only the second sentence is acceptable. Would you agree?