#!/usr/bin/perl
use strict;
use warnings;

my $first = 39703 * 86400 + 4 * 3600;
my $second = 39652 * 86400;
my $diff = 25;
my $rate = ($first - $second) / $diff;
my $estimated_duration = int($first / $rate);
my $estimated_finish_time = scalar localtime(time + $estimated_duration);

print "Estimated duration: $estimated_duration seconds\n";
print "Estimated finish time: $estimated_finish_time (if we start now)\n";