来自MySQL的内部时间表示是什么？

Question

这是我当前项目MySQL控制台的一个快照：

+---------------------+-----------+-----------+
| date_time_local     | delta_kWh | prod_hour |
+---------------------+-----------+-----------+
| 2014-05-25 05:20:00 |     0.169 |         5 |
| 2014-05-25 06:00:00 |     0.751 |         6 |
| 2014-05-25 07:00:00 |     0.743 |         7 |
| 2014-05-25 08:00:00 |     0.830 |         8 |
+---------------------+-----------+-----------+

MySQL将prod小时显示为数字，但在客户收到的结果中，相应的值为：

[{"date_time_local":"2014-05-25 05:20:00","delta_kWh":"0.169","prod_hour":504403295704449000},
{"date_time_local":"2014-05-25 06:00:00","delta_kWh":"0.751","prod_hour":576460889742377000},
{"date_time_local":"2014-05-25 07:00:00","delta_kWh":"0.743","prod_hour":648518483780304900},
{"date_time_local":"2014-05-25 08:00:00","delta_kWh":"0.830","prod_hour":720576077818232800}]

服务器返回的生产小时是多少？ 我的MySQL查询是：

var resQuery = "SELECT concat(date_time_local) AS date_time_local, SUM(delta_kWh) AS delta_kWh,     EXTRACT(HOUR FROM date_time_local) AS prod_hour FROM local_solar_consumption WHERE date_time_local BETWEEN '" + jsonRequestObj.startdate + "' AND '" + jsonRequestObj.enddate + "' GROUP BY prod_hour";

编辑： 我发送结果数组：     that.resultsToSocket（resQuery，“ownProdCons”，plotcase，socket）;     rows.push（plotcase）;                 rows.push（plottype）;                 socket.emit（'got_data'，rows）;

并在客户端字符串化结果：

 socket.on('got_data', function (data) {

                em.plotCharts(data);

                console.log(JSON.stringify(data));
                //alert(JSON.stringify(data));


              });