Bug in @filter() for day indexed edge

In fact, look at the return from q0 and q1 in this:

{
  q0(func:has(hours.tracked),first:2) @filter(gt(hours.tracked,2019-01-01)){
      hours.tracked
  }
  q1(func:has(hours.tracked),first:2) @filter(gt(hours.tracked,2020-01-01)){
      hours.tracked
  }
 	q2(func:gt(hours.tracked,2019-01-01),first:2){
      hours.tracked
  }
 	q3(func:gt(hours.tracked,2020-01-01),first:2){
      hours.tracked
  }
}

Gives:

{
  "data": {
    "q0": [
      {
        "hours.tracked": "2019-10-17T00:00:00Z"
      },
      {
        "hours.tracked": "2019-10-24T00:00:00Z"
      }
    ],
    "q1": [],
    "q2": [
      {
        "hours.tracked": "2020-01-15T00:00:00Z"
      },
      {
        "hours.tracked": "2020-01-22T00:00:00Z"
      }
    ],
    "q3": [
      {
        "hours.tracked": "2020-01-15T00:00:00Z"
      },
      {
        "hours.tracked": "2020-01-22T00:00:00Z"
      }
    ]
  },
  "extensions": {
    "server_latency": {
      "parsing_ns": 365100,
      "processing_ns": 37904400,
      "encoding_ns": 39000,
      "assign_timestamp_ns": 2104500,
      "total_ns": 41061800
    },
    "txn": {
      "start_ts": 774739
    },
    "metrics": {
      "num_uids": {
        "hours.tracked": 8
      }
    }
  }
}

q0 has no 2020 entries, q1 nothing, q3 and q4 being what I would expect to get from q0 and q1.