The following query follows the API and because of the _date is not working.
Make sure this is working and fully supported.

query = """
[
{
"AddEntity" : {
"class" : "doctor",
"properties": {
"name": "Mark",
"age": 5,
"speciality": "brains",
"dob": {"_date", "Sat Nov 1 18:59:24 PDT 1930"}
}
}
}
]
"""