From your description it seems as if you need an if between the next and the (($day...

Something like

   next if (($day_counter == 0)&&(substr($_,9,2)<17));
   next if (($day_counter == 1)&&(substr($_,9,2)>16));
[download]

Update: D'oh Abigail-II was much faster with his reply.

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Of all the things I've lost in my life, its my mind I miss the most.