Python多维数据集Olap Framework日期PointCut

所以我试图用Python Cubes Framework实现一些BI，但是遇到了一些问题。

基本上，我试图做一个“简单的” PointCut /切片和骰子，我没有任何运气。我在PostGis中使用PostgreSQL数据库。

我的model.json是：

{
    "dimensions": [
        {"name": "user", "attributes": ["id", "username"]},
        {"name": "resources", "attributes": ["id", "resource_simple_name"]},
        {"name":"created_on", "role": "time"}
    ],
    "cubes": [
        {
            "name": "users_resources_likes",
            "dimensions": ["user", "resources", "created_on"],
            "mappings": {
                "user.id": "auth_user.id",
                "user.username": "auth_user.username",
                "resources.id": "resources.id",
                "resources.resource_simple_name": "resources.resource_simple_name",
                "created_on": "created_on"
            },
            "joins": [
                {
                    "master": "user_id",
                    "detail": "auth_user.id"
                },
                {
                    "master": "resource_id",
                    "detail": "resources.id"
                }
            ]
        }

    ]
}

如果我尝试在切片机上做一个日期的poincut

aggregate?drilldown=created_on&cut=created_on:2012

我得到一个 DataError: (DataError) invalid input syntax for type timestamp with time zone: "2012"

搜索了一会后，我读到它可能是因为我的postgresql数据库有时间戳记：

created_on timestamp with time zone NOT NULL DEFAULT '2014-02-10 00:00:00+00'::timestamp with time zone, 所以我试图做：

?drilldown=created_on&cut=created_on:2012-09-15T09:37:59+00:00

我得到了：

{
error: "unknown_user_error",
message: "Wrong dimension cut string: 'created_on:2012-09-15T09:37:59 00:00'"
}

我究竟做错了什么？是我的问题model.json吗？