<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Cron:etc/crontab.xsd">
<group id="cpm_order_cron">
    <job name="cpm_order_reminder" instance="CpmOrderCronContractEndReminder" method="execute">
        <schedule>15 10 * * *</schedule>
    </job>
</group>

public function execute()
    {
            $fh = fopen("/var/www/html/var/log/cron_log","a");
            fwrite($fh,"Start Time: ".date("Y-m-d H:i:s")."n");
            $model = $this->OrderPriceFactory->create();
            $orders = $model->getCollection();


            foreach($orders->getItems() as $op)
            {
                    fwrite($fh,"Contract End: ".$op->getContractEnd()."n");
                    $order = $this->OrderFactory->create()->load($op->getOrderId());
                    $customer = $this->objectManager->get("MagentoCustomerModelCustomer")->load($order->getCustomerId());
                    $sendData = array(
                            "op_id"=>$op->getId(),
                            "order_id"=>$op->getOrderId(),
                            "contract_id"=>$order->getIncrementId(),
                            "order_status"=>$order->getStatusLabel(),
                            "purchased_date"=>$order->getCreatedAt(),
                            "contract_start"=>$op->getContractStart(),
                            "contract_end"=>$op->getContractEnd(),
                            "customer_name"=>$customer->getFirstname(),
                            "customer_email"=>$customer->getEmail()
                    );
                     $this->sendemail($customer->getEmail(),$sendData);
            }
            fclose($fh);
    }