map { ($date, $magnitude) = (split',')[3,4]; [$_, normalize($date), $magnitude] } #### sub normalize { my $value = shift; my ($hours, $minutes, $seconds) = $value =~ m/(\d{2}):(\d{2}):(\d{2}\.\d{3})$/; return int((1000 * $seconds + $minutes * 60 + $hours * 3600)/300); }