“time ago” function used on this site

For me, seeing long it’s been since I did something is more valuable than the date. Kind of an Instagram-inspired way to display the date. Have to pass current WP UTC as argument. Accurate down to seconds-ago.

function time_ago($tm,$rcs = 0) {
   $cur_tm = time(); $dif = $cur_tm-$tm;
   $pds = array('second','minute','hour','day','week','month','year','decade');
   $lngh = array(1,60,3600,86400,604800,2630880,31570560,315705600);
   for($v = sizeof($lngh)-1; ($v >= 0)&&(($no = $dif/$lngh[$v])<=1); $v--); if($v < 0) $v = 0; $_tm = $cur_tm-($dif%$lngh[$v]);

   $no = floor($no); if($no <> 1) $pds[$v] .='s'; $x=sprintf("%d %s ",$no,$pds[$v]);
   if(($rcs == 1)&&($v >= 1)&&(($cur_tm-$_tm) > 0)) $x .= time_ago($_tm);
   return $x;
}