Day before today (9)
I believe the answer is:
yesterday
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">day before today</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 yesterday that I've seen before include "Song about break-up" , "Number" , "Song (of the recent past?)" , "short time ago" , "Beatles hit - Thursday" .)