express.js中mongoose中与时刻日期相关的查询(结果为零)

const mongoose = require('mongoose');

const eventSchema = new mongoose.Schema({
  timestamp: {
    type: Date,
    default: Date.now
  },
  // 其他字段...
});

const Event = mongoose.model('Event', eventSchema);

const express = require('express');
const router = express.Router();

router.get('/events/count', async (req, res) => {
  const startDate = new Date('2022-01-01');
  const endDate = new Date('2022-01-31');

  try {
    const count = await Event.countDocuments({
      timestamp: {
        $gte: startDate,
        $lt: endDate
      }
    });

    res.json({ count });
  } catch (error) {
    res.status(500).json({ error: 'An error occurred' });
  }
});

module.exports = router;

const express = require('express');
const mongoose = require('mongoose');
const eventsRouter = require('./routes/events');

const app = express();

// 连接到MongoDB数据库
mongoose.connect('mongodb://localhost/mydatabase', {
  useNewUrlParser: true,
  useUnifiedTopology: true
}).then(() => {
  console.log('Connected to MongoDB');
}).catch((error) => {
  console.error('Failed to connect to MongoDB', error);
});

// 添加路由
app.use('/api', eventsRouter);

// 启动服务器
app.listen(3000, () => {
  console.log('Server started on port 3000');
});