<?php

echo '
<form method="post">
Days:<input name="$days" type="text" size="10" />
Hours:<input type="text" name="$hours" size="10"/>
Minutes:<input type="text" name="$minutes" size="10"/>
Seconds:<input type="text" name="$seconds" size="10"/>
<input type="submit" name="submit" />
</form>
<br />
';

$seconds=( ($_POST['$days']*86400) + ($_POST['$hours']*3600) + ($_POST['$minutes']*60) + $_POST['$seconds'] );
echo 'Event Time/Date: '.date('Y-m-d H:i:s', strtotime(+$seconds.' second));

?>