- 忽略milliseconds, length = 10
"created_at": 1360019238
- length = 13
"created_at": 1360019238123
- 忽略milliseconds
"created_at": "2008-01-14T04:33:35Z"
"created_at": "2008-01-14T04:33:35.123Z"
"created_at": "Sat, 21 Aug 2010 22:31:20 +0000"
"created_at": 1360019238
"created_at": 1360019238123
"created_at": "2008-01-14T04:33:35Z"
"created_at": "2008-01-14T04:33:35.123Z"
"created_at": "Sat, 21 Aug 2010 22:31:20 +0000"