{
  "date": "2026-10-31",
  "synthetic": true,
  "engineHash": "819DABF6A28FEBF11AC2D173CD0274AF2576C2DB42CDFE9F748E8A20215EC990",
  "runtime": {
    "node": "v24.22.1",
    "icu": "78.3",
    "tz": "2026e"
  },
  "cases": [
    {
      "id": "midnight-rule",
      "input": {
        "calendar": "solar",
        "year": "2024",
        "month": "3",
        "day": "20",
        "time": "23:30",
        "gender": "1",
        "unknown": false,
        "leap": false,
        "zone": "Asia/Shanghai",
        "longitude": "120",
        "solar": false,
        "sect": "2",
        "fold": "earlier",
        "city": "custom"
      },
      "utc": "2024-03-20 15:30",
      "civil": "2024-03-20 23:30",
      "adjusted": "2024-03-20 23:30",
      "offsetMinutes": 480,
      "pillars": [
        {
          "key": "Year",
          "name": "Jia Chen",
          "gz": "甲辰"
        },
        {
          "key": "Month",
          "name": "Ding Mao",
          "gz": "丁卯"
        },
        {
          "key": "Day",
          "name": "Gui Wei",
          "gz": "癸未"
        },
        {
          "key": "Time",
          "name": "Jia Zi",
          "gz": "甲子"
        }
      ],
      "variants": [],
      "dayMaster": {
        "char": "癸",
        "name": "Gui",
        "element": "Water",
        "polarity": "Yin"
      }
    },
    {
      "id": "zi-rule",
      "input": {
        "calendar": "solar",
        "year": "2024",
        "month": "3",
        "day": "20",
        "time": "23:30",
        "gender": "1",
        "unknown": false,
        "leap": false,
        "zone": "Asia/Shanghai",
        "longitude": "120",
        "solar": false,
        "sect": "1",
        "fold": "earlier",
        "city": "custom"
      },
      "utc": "2024-03-20 15:30",
      "civil": "2024-03-20 23:30",
      "adjusted": "2024-03-20 23:30",
      "offsetMinutes": 480,
      "pillars": [
        {
          "key": "Year",
          "name": "Jia Chen",
          "gz": "甲辰"
        },
        {
          "key": "Month",
          "name": "Ding Mao",
          "gz": "丁卯"
        },
        {
          "key": "Day",
          "name": "Jia Shen",
          "gz": "甲申"
        },
        {
          "key": "Time",
          "name": "Jia Zi",
          "gz": "甲子"
        }
      ],
      "variants": [],
      "dayMaster": {
        "char": "甲",
        "name": "Jia",
        "element": "Wood",
        "polarity": "Yang"
      }
    },
    {
      "id": "next-midnight",
      "input": {
        "calendar": "solar",
        "year": "2024",
        "month": "3",
        "day": "21",
        "time": "00:30",
        "gender": "1",
        "unknown": false,
        "leap": false,
        "zone": "Asia/Shanghai",
        "longitude": "120",
        "solar": false,
        "sect": "2",
        "fold": "earlier",
        "city": "custom"
      },
      "utc": "2024-03-20 16:30",
      "civil": "2024-03-21 00:30",
      "adjusted": "2024-03-21 00:30",
      "offsetMinutes": 480,
      "pillars": [
        {
          "key": "Year",
          "name": "Jia Chen",
          "gz": "甲辰"
        },
        {
          "key": "Month",
          "name": "Ding Mao",
          "gz": "丁卯"
        },
        {
          "key": "Day",
          "name": "Jia Shen",
          "gz": "甲申"
        },
        {
          "key": "Time",
          "name": "Jia Zi",
          "gz": "甲子"
        }
      ],
      "variants": [],
      "dayMaster": {
        "char": "甲",
        "name": "Jia",
        "element": "Wood",
        "polarity": "Yang"
      }
    },
    {
      "id": "before-hour-boundary",
      "input": {
        "calendar": "solar",
        "year": "2024",
        "month": "3",
        "day": "20",
        "time": "22:59",
        "gender": "1",
        "unknown": false,
        "leap": false,
        "zone": "Asia/Shanghai",
        "longitude": "120",
        "solar": false,
        "sect": "2",
        "fold": "earlier",
        "city": "custom"
      },
      "utc": "2024-03-20 14:59",
      "civil": "2024-03-20 22:59",
      "adjusted": "2024-03-20 22:59",
      "offsetMinutes": 480,
      "pillars": [
        {
          "key": "Year",
          "name": "Jia Chen",
          "gz": "甲辰"
        },
        {
          "key": "Month",
          "name": "Ding Mao",
          "gz": "丁卯"
        },
        {
          "key": "Day",
          "name": "Gui Wei",
          "gz": "癸未"
        },
        {
          "key": "Time",
          "name": "Gui Hai",
          "gz": "癸亥"
        }
      ],
      "variants": [],
      "dayMaster": {
        "char": "癸",
        "name": "Gui",
        "element": "Water",
        "polarity": "Yin"
      }
    },
    {
      "id": "after-hour-boundary",
      "input": {
        "calendar": "solar",
        "year": "2024",
        "month": "3",
        "day": "20",
        "time": "23:01",
        "gender": "1",
        "unknown": false,
        "leap": false,
        "zone": "Asia/Shanghai",
        "longitude": "120",
        "solar": false,
        "sect": "2",
        "fold": "earlier",
        "city": "custom"
      },
      "utc": "2024-03-20 15:01",
      "civil": "2024-03-20 23:01",
      "adjusted": "2024-03-20 23:01",
      "offsetMinutes": 480,
      "pillars": [
        {
          "key": "Year",
          "name": "Jia Chen",
          "gz": "甲辰"
        },
        {
          "key": "Month",
          "name": "Ding Mao",
          "gz": "丁卯"
        },
        {
          "key": "Day",
          "name": "Gui Wei",
          "gz": "癸未"
        },
        {
          "key": "Time",
          "name": "Jia Zi",
          "gz": "甲子"
        }
      ],
      "variants": [],
      "dayMaster": {
        "char": "癸",
        "name": "Gui",
        "element": "Water",
        "polarity": "Yin"
      }
    },
    {
      "id": "unknown-hour",
      "input": {
        "calendar": "solar",
        "year": "2024",
        "month": "3",
        "day": "20",
        "time": "12:00",
        "gender": "1",
        "unknown": true,
        "leap": false,
        "zone": "Asia/Shanghai",
        "longitude": "120",
        "solar": false,
        "sect": "2",
        "fold": "earlier",
        "city": "custom"
      },
      "utc": "2024-03-20 04:00",
      "civil": "2024-03-20 12:00",
      "adjusted": "2024-03-20 12:00",
      "offsetMinutes": 480,
      "pillars": [
        {
          "key": "Year",
          "name": "Jia Chen",
          "gz": "甲辰"
        },
        {
          "key": "Month",
          "name": "Ding Mao",
          "gz": "丁卯"
        },
        {
          "key": "Day",
          "name": "Gui Wei",
          "gz": "癸未"
        }
      ],
      "variants": [
        "Jia Chen · Ding Mao · Gui Wei"
      ],
      "dayMaster": {
        "char": "癸",
        "name": "Gui",
        "element": "Water",
        "polarity": "Yin"
      }
    }
  ],
  "assertions": "Same instant across day-boundary settings; Day differs and Year/Month do not; next civil day agrees with Zi-rule Day; 22:59/23:01 changes Hour but not midnight-rule Day; unknown excludes Hour.",
  "scope": "Implementation behavior only, not a scientific validation of interpretation."
}