隐藏API的日期格式是什么？

在下面的json响应中，createdDate和UpdatedDate的日期格式是什么？我不确定如何反向工作以查找api用于日期的格式。我在文档中的任何地方都找不到。

{
"size": 1,
"limit": 25,
"isLastPage": true,
"values": [
    {
        "id": 101,
        "version": 1,
        "title": "Talking Nerdy",
        "description": "It’s a kludge, but put the tuple from the database in the cache.",
        "state": "OPEN",
        "open": true,
        "closed": false,
        "createdDate": 1359075920,
        "updatedDate": 1359085920,
        "fromRef": {
            "id": "refs/heads/feature-ABC-123",
            "repository": {
                "slug": "my-repo",
                "name": null,
                "project": {
                    "key": "PRJ"
                }
            }
        },
        "toRef": {
            "id": "refs/heads/master",
            "repository": {
                "slug": "my-repo",
                "name": null,
                "project": {
                    "key": "PRJ"
                }
            }
        },
        "locked": false,
        "author": {
            "user": {
                "name": "tom",
                "emailAddress": "[email protected]",
                "id": 115026,
                "displayName": "Tom",
                "active": true,
                "slug": "tom",
                "type": "NORMAL"
            },
            "role": "AUTHOR",
            "approved": true
        },
        "reviewers": [
            {
                "user": {
                    "name": "jcitizen",
                    "emailAddress": "[email protected]",
                    "id": 101,
                    "displayName": "Jane Citizen",
                    "active": true,
                    "slug": "jcitizen",
                    "type": "NORMAL"
                },
                "role": "REVIEWER",
                "approved": true
            }
        ],
        "participants": [
            {
                "user": {
                    "name": "dick",
                    "emailAddress": "[email protected]",
                    "id": 3083181,
                    "displayName": "Dick",
                    "active": true,
                    "slug": "dick",
                    "type": "NORMAL"
                },
                "role": "PARTICIPANT",
                "approved": false
            },
            {
                "user": {
                    "name": "harry",
                    "emailAddress": "[email protected]",
                    "id": 99049120,
                    "displayName": "Harry",
                    "active": true,
                    "slug": "harry",
                    "type": "NORMAL"
                },
                "role": "PARTICIPANT",
                "approved": true
            }
        ],
        "link": {
            "url": "http://link/to/pullrequest",
            "rel": "self"
        },
        "links": {
            "self": [
                {
                    "href": "http://link/to/pullrequest"
                }
            ]
        }
    }
],
"start": 0

}