#!/usr/local/bin/perl
use strict;
use warnings;
use Regexp::Assemble;
use Math::BigFloat lib => 'GMP';

my $maxdigits = shift || 1000;
my $pi = Math::BigFloat->bpi($maxdigits) . '';
$pi =~ s/3\./3/;

my $re_date = do {
    my $ra = Regexp::Assemble->new;
    for my $m ( 1 .. 12 ) {
        my $ld = (qw/31 29 31 30 31 30 31 31 30 31 30 31/)[ $m - 1 ];
        for my $d ( 1 .. $ld ) {
            $ra->add( sprintf "%02d%02d", $m, $d );
        }
    }
    $ra->re;
};
my $re_hh = do {
    my $ra = Regexp::Assemble->new;
    for my $h ( 0 .. 23 ) {
        $ra->add( sprintf "%02d", $h );
    }
    $ra->re;
};
my $re_mm = do {
    my $ra = Regexp::Assemble->new;
    for my $h ( 0 .. 59 ) {
        $ra->add( sprintf "%02d", $h );
    }
    $ra->re;
};
my $re_ss = $re_mm;
my $re_piday = qr/($re_date)($re_hh)($re_mm)($re_ss)/;
warn $re_piday, "\n";
while ( $pi =~ /$re_piday/g ) {
    print "$1 $2:$3:$4 @", pos($pi) - 10, "\n";
}