如何使用MongoDB将几个小时的行数合并为一天？

{ "_id": 1, "timestamp": ISODate("2023-04-01T00:00:00Z"), "count": 100 }
{ "_id": 2, "timestamp": ISODate("2023-04-01T01:00:00Z"), "count": 150 }
{ "_id": 3, "timestamp": ISODate("2023-04-01T02:00:00Z"), "count": 200 }
...

db.logs.aggregate([
  {
    $match: {
      timestamp: { $gte: ISODate("2023-04-01T00:00:00Z"), $lt: ISODate("2023-04-02T00:00:00Z") }
    }
  },
  {
    $group: {
      _id: { $dateToString: { format: "%Y-%m-%d", date: "$timestamp" } },
      total_count: { $sum: "$count" }
    }
  }
])

db.logs.aggregate([
  {
    $match: {
      timestamp: { $gte: ISODate("2023-04-01T00:00:00Z"), $lt: ISODate("2023-04-02T00:00:00Z") }
    }
  },
  {
    $group: {
      _id: { $dateToString: { format: "%Y-%m-%d", date: "$timestamp" } },
      total_count: { $sum: "$count" }
    }
  }
])