while (my ($IP, $hUserAgents) = each(%hRequests)) {
      next if #IP is boring;
      while (my ($userAgent, $hDates = each(%$hUserAgents)) {
          next if #user agent is boring;
          while (my ($date, $aRequests) = each(%$hDates)) {
             #do something if date is in range
             #wanted for $IP, $userAgent
          }
      }
   }