{"aggregate": "collectionA","pipeline": [{"$match": {"creation_date": {"$gte": ISODate("2016-05-09T06:48:11.526+01:00")}},"$lookup": {"from": "collectionB","localField": "a_id","foreignField": "_id","as": "b"}}]}
"creation_date": {"$gte": ISODate("2016-05-09T06:48:11.526+01:00")}
"creation_date": {
"$gte": {"$date" : "2016-05-09T06:48:11.526+01:00"}
"$lte": "ISODate(\"xxxxx\")" - this is a valid JSON but not a ISODate operator
"$lte": ISODate("xxxxx") - this is a invalid JSON but valid ISODate operator
"creation_date": {"$gte": {"$date": "2016-05-01T11:13:27.519Z"}