#!/usr/bin/perl -w

use Time::Local;
use strict;

my $last_ts = 0;
my $last_line;

while ( my $line = <> ) {
  chomp $line;

  my @tmp = ( $line =~ /^(\d{2})\/(\d{2})\/(\d{2})\s+(\d{2}):(\d{2}):(\d{2})/) ;
  if ( @tmp ) {
    my ($mm,$dd,$yy,$HH,$MM,$SS) = @tmp;
    #print "$mm,$dd,$yy,$HH,$MM,$SS\n";
    if ( $yy < 38 ) {
      $yy += 2000;
    } else {
      $yy += 1900;
    }
    my $ts = timelocal($SS,$MM,$HH,$dd,$mm - 1,$yy);

    if ( $last_ts != 0 ) {
      my $ts_diff = $ts - $last_ts;
      #print "diff was $ts_diff\n";
      my $ts_diff_min = $ts_diff / 60;
      if ( $ts_diff_min > 30 ) {
        print "gap detected of $ts_diff_min minutes\n";
        print "last line: $last_line\n";
        print "current line: $line\n";
      }
    }

    $last_line = $line;
    $last_ts = $ts;

  }

}