Dated of last month (6)
I believe the answer is:
ultimo
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">dated of last month</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for ultimo that I've seen before include "In full, last month in business correspondence" , "Previous month" , "In commerce, of last month" , "Indicating last month, usually abbreviated" , "recently" .)