Ego Ticker PHP Change

<?php
date_default_timezone_set('America/New_York');
$myFileYesterday = "reddit-" . date("Ymd", time() - 86400). ".txt";
$myFileToday = "reddit-" . date("Ymd"). ".txt";
$fhYesterday = fopen($myFileYesterday, 'r');
$fhToday = fopen($myFileToday, 'r');
$yesterdayScore = fread($fhYesterday, 50);
$todayScore = fread($fhToday, 50);
$change = $todayScore - $yesterdayScore;
if ($change == 0)
    echo "Unch";
if ($change > 0)
{
    echo "+";
    echo $change;
    }
if ($change < 0)
{
    echo $change;
}

fclose($fhToday);
fclose($fhYesterday);

$checkfile = "reddit-" . date("Ymd", time() - 172800). ".txt";

if (is_file($checkfile)) {
    unlink($checkfile);
}
?>