$cache{$yearmonth}+$days*(24*60*60)+$hours*(60*60)+$mins*60+$secs;

##</code><code>##

($cache{substr($date,0,10)}||=time_to_unix(substr($date,0,10)))
   + substr($date,10,2)*60 + substr($date,12,2);

##</code><code>##

$cache{$year.$month}