$server_seed = "6c8932c27fcb90be2a8ab24bc9bc39c6776fc3704d57915d8fad2b710262d6cf";
$day = "20190405";
$round_id = "1";
$hash = hash("sha256", $server_seed . "-" . $day . "-" . $round_id);
$roll = hexdec(substr($hash, 0, 8)) % 15;
echo "Round $round_id = $roll";

$server_seed = "6c8932c27fcb90be2a8ab24bc9bc39c6776fc3704d57915d8fad2b710262d6cf";
$day = "20190405";
$round_id = "1";
$hash = hash("sha256", $server_seed . "-" . $day . "-" . $round_id);
$dice_1 = hexdec(substr($hash, 8, 8)) % 6 + 1;
$dice_2 = hexdec(substr($hash, 16, 8)) % 6 + 1;
$dice_3 = hexdec(substr($hash, 24, 8)) % 6 + 1;
echo "Round $round_id = [$dice_1,$dice_2,$dice_3]";