let simpleQuery = (startDate, millis) => {
  return Entry.aggregate([{
    $match: {
      date: {
        $gte: startDate
      }
    }
  },
  {
    $project: {
      cpu: '$data.cpu',
      date: 1
    }
  },
  {
    $group: {
      _id: {
        $floor: {
          $divide: [{
            $subtract: ['$date', startDate]
          }, millis]
        }
      },
      avgCpu: {
        $avg: '$cpu'
      },
      avgDate: {
        $avg: {
          $sum: {
            $subtract: ['$date', TheEpoch]
          }
        }
      }
    }
  },
  {
    $project: {
      _id: 0,
      avg: '$avgCpu',
      date: '$avgDate'
    }
  },
  {
    $sort: {
      date: 1
    }
  }
  ])
}