Chart boundary inputs and calculation conventions

24 synthetic inputs cover solar terms, Zi hour, lunar conversion and solar-time rollover, with explicit reference limits.

Check solar time and rollover

What these checks establish

Calendar conversion and solar-term month boundaries have stated external references. Zi-hour cases document a convention rather than prove every school wrong. Solar-time records compare two approximations rather than certify astronomical accuracy. Open the detailed records only for the input you need to check.

What the records establish

The current Go engine generated six inputs in each of four groups. Twelve match only the declared reference fields and scope. Six record the Zi-hour convention with an independent day-cycle audit pending. Six compare a second NOAA approximation without an astronomical accuracy pass. There is no claim that all 24 have passed authoritative validation.

Check solar time and rollover

How to use the references

J inputs fall two minutes before and after published CWA 2024 solar-term minutes; expected month pillars follow the jie sequence and Five Tiger rule. This is not second-level validation. L inputs compare civil dates with HKO 2023/2024 CSV records; they do not endorse a Ziwei leap-month convention.

Conventions and time-zone limits

Z inputs disable solar correction and show this project’s midnight day boundary and 23:00 start of Zi hour. A different declared day boundary is not automatically an error. All T clock inputs are deliberately UTC+8, including a west-longitude teaching value. Global historical time zones and daylight saving are not implemented here.

Version and corrections

Record version 2026-10-26.1; lunar-go v1.4.6. Run go run ./cmd/chart-validation in the API module to reproduce the inputs. Regression tests detect drift; they do not replace external validation. Corrections must update inputs, references, text and tests together. No named professional reviewer is claimed.

Solar-term boundaries (6)

J01 · Declared reference fields match

Input
2024-02-04T16:25:00+08:00
Production output
Year / month / day / hour: 癸卯 · 乙丑 · 戊戌 · 庚申
Independent reference and scope

2024-02-04 16:27 +08:00 · 乙丑

https://www.cwa.gov.tw/Data/service/notice/download/Publish_20231127145652.pdf (printed page 4); traditional jie month sequence

Expand raw machine fields
{
  "id": "J01",
  "category": "solar-terms",
  "input": "2024-02-04T16:25:00+08:00",
  "actual": {
    "year": "癸卯",
    "month": "乙丑",
    "day": "戊戌",
    "hour": "庚申"
  },
  "reference": {
    "expectedMonth": "乙丑",
    "publishedMinute": "2024-02-04 16:27 +08:00",
    "scope": "minute-separated month boundary only; not second-level validation",
    "source": "https://www.cwa.gov.tw/Data/service/notice/download/Publish_20231127145652.pdf (printed page 4); traditional jie month sequence",
    "term": "立春"
  },
  "status": "reference-match"
}

J02 · Declared reference fields match

Input
2024-02-04T16:29:00+08:00
Production output
Year / month / day / hour: 甲辰 · 丙寅 · 戊戌 · 庚申
Independent reference and scope

2024-02-04 16:27 +08:00 · 丙寅

https://www.cwa.gov.tw/Data/service/notice/download/Publish_20231127145652.pdf (printed page 4); traditional jie month sequence

Expand raw machine fields
{
  "id": "J02",
  "category": "solar-terms",
  "input": "2024-02-04T16:29:00+08:00",
  "actual": {
    "year": "甲辰",
    "month": "丙寅",
    "day": "戊戌",
    "hour": "庚申"
  },
  "reference": {
    "expectedMonth": "丙寅",
    "publishedMinute": "2024-02-04 16:27 +08:00",
    "scope": "minute-separated month boundary only; not second-level validation",
    "source": "https://www.cwa.gov.tw/Data/service/notice/download/Publish_20231127145652.pdf (printed page 4); traditional jie month sequence",
    "term": "立春"
  },
  "status": "reference-match"
}

J03 · Declared reference fields match

Input
2024-03-05T10:21:00+08:00
Production output
Year / month / day / hour: 甲辰 · 丙寅 · 戊辰 · 丁巳
Independent reference and scope

2024-03-05 10:23 +08:00 · 丙寅

https://www.cwa.gov.tw/Data/service/notice/download/Publish_20231127145652.pdf (printed page 4); traditional jie month sequence

Expand raw machine fields
{
  "id": "J03",
  "category": "solar-terms",
  "input": "2024-03-05T10:21:00+08:00",
  "actual": {
    "year": "甲辰",
    "month": "丙寅",
    "day": "戊辰",
    "hour": "丁巳"
  },
  "reference": {
    "expectedMonth": "丙寅",
    "publishedMinute": "2024-03-05 10:23 +08:00",
    "scope": "minute-separated month boundary only; not second-level validation",
    "source": "https://www.cwa.gov.tw/Data/service/notice/download/Publish_20231127145652.pdf (printed page 4); traditional jie month sequence",
    "term": "惊蛰"
  },
  "status": "reference-match"
}

J04 · Declared reference fields match

Input
2024-03-05T10:25:00+08:00
Production output
Year / month / day / hour: 甲辰 · 丁卯 · 戊辰 · 丁巳
Independent reference and scope

2024-03-05 10:23 +08:00 · 丁卯

https://www.cwa.gov.tw/Data/service/notice/download/Publish_20231127145652.pdf (printed page 4); traditional jie month sequence

Expand raw machine fields
{
  "id": "J04",
  "category": "solar-terms",
  "input": "2024-03-05T10:25:00+08:00",
  "actual": {
    "year": "甲辰",
    "month": "丁卯",
    "day": "戊辰",
    "hour": "丁巳"
  },
  "reference": {
    "expectedMonth": "丁卯",
    "publishedMinute": "2024-03-05 10:23 +08:00",
    "scope": "minute-separated month boundary only; not second-level validation",
    "source": "https://www.cwa.gov.tw/Data/service/notice/download/Publish_20231127145652.pdf (printed page 4); traditional jie month sequence",
    "term": "惊蛰"
  },
  "status": "reference-match"
}

J05 · Declared reference fields match

Input
2024-04-04T15:00:00+08:00
Production output
Year / month / day / hour: 甲辰 · 丁卯 · 戊戌 · 庚申
Independent reference and scope

2024-04-04 15:02 +08:00 · 丁卯

https://www.cwa.gov.tw/Data/service/notice/download/Publish_20231127145652.pdf (printed page 4); traditional jie month sequence

Expand raw machine fields
{
  "id": "J05",
  "category": "solar-terms",
  "input": "2024-04-04T15:00:00+08:00",
  "actual": {
    "year": "甲辰",
    "month": "丁卯",
    "day": "戊戌",
    "hour": "庚申"
  },
  "reference": {
    "expectedMonth": "丁卯",
    "publishedMinute": "2024-04-04 15:02 +08:00",
    "scope": "minute-separated month boundary only; not second-level validation",
    "source": "https://www.cwa.gov.tw/Data/service/notice/download/Publish_20231127145652.pdf (printed page 4); traditional jie month sequence",
    "term": "清明"
  },
  "status": "reference-match"
}

J06 · Declared reference fields match

Input
2024-04-04T15:04:00+08:00
Production output
Year / month / day / hour: 甲辰 · 戊辰 · 戊戌 · 庚申
Independent reference and scope

2024-04-04 15:02 +08:00 · 戊辰

https://www.cwa.gov.tw/Data/service/notice/download/Publish_20231127145652.pdf (printed page 4); traditional jie month sequence

Expand raw machine fields
{
  "id": "J06",
  "category": "solar-terms",
  "input": "2024-04-04T15:04:00+08:00",
  "actual": {
    "year": "甲辰",
    "month": "戊辰",
    "day": "戊戌",
    "hour": "庚申"
  },
  "reference": {
    "expectedMonth": "戊辰",
    "publishedMinute": "2024-04-04 15:02 +08:00",
    "scope": "minute-separated month boundary only; not second-level validation",
    "source": "https://www.cwa.gov.tw/Data/service/notice/download/Publish_20231127145652.pdf (printed page 4); traditional jie month sequence",
    "term": "清明"
  },
  "status": "reference-match"
}

Zi-hour and day boundaries (6)

Z01 · Convention recorded; independent audit pending

Input
2024-06-15 22:59 +08:00; no solar correction
Production output
Year / month / day / hour: 甲辰 · 庚午 · 庚戌 · 丁亥
Independent reference and scope

Midnight changes the day; Zi hour begins at 23:00. Independent day-cycle audit pending.

Declared implementation convention

Expand raw machine fields
{
  "id": "Z01",
  "category": "zi-hour",
  "input": "2024-06-15 22:59 +08:00; no solar correction",
  "actual": {
    "year": "甲辰",
    "month": "庚午",
    "day": "庚戌",
    "hour": "丁亥"
  },
  "reference": {
    "expected": "civil midnight changes day pillar; 23:00 starts Zi hour",
    "scope": "recorded convention; independent historical day-cycle audit pending",
    "source": "ganzi.go implementation convention"
  },
  "status": "convention-recorded"
}

Z02 · Convention recorded; independent audit pending

Input
2024-06-15 23:00 +08:00; no solar correction
Production output
Year / month / day / hour: 甲辰 · 庚午 · 庚戌 · 丙子
Independent reference and scope

Midnight changes the day; Zi hour begins at 23:00. Independent day-cycle audit pending.

Declared implementation convention

Expand raw machine fields
{
  "id": "Z02",
  "category": "zi-hour",
  "input": "2024-06-15 23:00 +08:00; no solar correction",
  "actual": {
    "year": "甲辰",
    "month": "庚午",
    "day": "庚戌",
    "hour": "丙子"
  },
  "reference": {
    "expected": "civil midnight changes day pillar; 23:00 starts Zi hour",
    "scope": "recorded convention; independent historical day-cycle audit pending",
    "source": "ganzi.go implementation convention"
  },
  "status": "convention-recorded"
}

Z03 · Convention recorded; independent audit pending

Input
2024-06-15 23:59 +08:00; no solar correction
Production output
Year / month / day / hour: 甲辰 · 庚午 · 庚戌 · 丙子
Independent reference and scope

Midnight changes the day; Zi hour begins at 23:00. Independent day-cycle audit pending.

Declared implementation convention

Expand raw machine fields
{
  "id": "Z03",
  "category": "zi-hour",
  "input": "2024-06-15 23:59 +08:00; no solar correction",
  "actual": {
    "year": "甲辰",
    "month": "庚午",
    "day": "庚戌",
    "hour": "丙子"
  },
  "reference": {
    "expected": "civil midnight changes day pillar; 23:00 starts Zi hour",
    "scope": "recorded convention; independent historical day-cycle audit pending",
    "source": "ganzi.go implementation convention"
  },
  "status": "convention-recorded"
}

Z04 · Convention recorded; independent audit pending

Input
2024-06-16 00:00 +08:00; no solar correction
Production output
Year / month / day / hour: 甲辰 · 庚午 · 辛亥 · 戊子
Independent reference and scope

Midnight changes the day; Zi hour begins at 23:00. Independent day-cycle audit pending.

Declared implementation convention

Expand raw machine fields
{
  "id": "Z04",
  "category": "zi-hour",
  "input": "2024-06-16 00:00 +08:00; no solar correction",
  "actual": {
    "year": "甲辰",
    "month": "庚午",
    "day": "辛亥",
    "hour": "戊子"
  },
  "reference": {
    "expected": "civil midnight changes day pillar; 23:00 starts Zi hour",
    "scope": "recorded convention; independent historical day-cycle audit pending",
    "source": "ganzi.go implementation convention"
  },
  "status": "convention-recorded"
}

Z05 · Convention recorded; independent audit pending

Input
2024-06-16 00:59 +08:00; no solar correction
Production output
Year / month / day / hour: 甲辰 · 庚午 · 辛亥 · 戊子
Independent reference and scope

Midnight changes the day; Zi hour begins at 23:00. Independent day-cycle audit pending.

Declared implementation convention

Expand raw machine fields
{
  "id": "Z05",
  "category": "zi-hour",
  "input": "2024-06-16 00:59 +08:00; no solar correction",
  "actual": {
    "year": "甲辰",
    "month": "庚午",
    "day": "辛亥",
    "hour": "戊子"
  },
  "reference": {
    "expected": "civil midnight changes day pillar; 23:00 starts Zi hour",
    "scope": "recorded convention; independent historical day-cycle audit pending",
    "source": "ganzi.go implementation convention"
  },
  "status": "convention-recorded"
}

Z06 · Convention recorded; independent audit pending

Input
2024-06-16 01:00 +08:00; no solar correction
Production output
Year / month / day / hour: 甲辰 · 庚午 · 辛亥 · 己丑
Independent reference and scope

Midnight changes the day; Zi hour begins at 23:00. Independent day-cycle audit pending.

Declared implementation convention

Expand raw machine fields
{
  "id": "Z06",
  "category": "zi-hour",
  "input": "2024-06-16 01:00 +08:00; no solar correction",
  "actual": {
    "year": "甲辰",
    "month": "庚午",
    "day": "辛亥",
    "hour": "己丑"
  },
  "reference": {
    "expected": "civil midnight changes day pillar; 23:00 starts Zi hour",
    "scope": "recorded convention; independent historical day-cycle audit pending",
    "source": "ganzi.go implementation convention"
  },
  "status": "convention-recorded"
}

Lunar dates and leap months (6)

L01 · Declared reference fields match

Input
2023-03-21; UTC+8 calendar date
Production output
2023-2-30 · leap=false
Independent reference and scope

2023-2-30 · leap=false

https://data.weather.gov.hk/weatherAPI/hko_data/calendar/nongli_calendar_2023.csv

Expand raw machine fields
{
  "id": "L01",
  "category": "lunar-calendar",
  "input": "2023-03-21; UTC+8 calendar date",
  "actual": {
    "year": 2023,
    "month": 2,
    "day": 30,
    "isLeapMonth": false
  },
  "reference": {
    "expected": {
      "year": 2023,
      "month": 2,
      "day": 30,
      "isLeapMonth": false
    },
    "scope": "civil calendar conversion only; not Ziwei leap-month chart convention",
    "source": "https://data.weather.gov.hk/weatherAPI/hko_data/calendar/nongli_calendar_2023.csv"
  },
  "status": "reference-match"
}

L02 · Declared reference fields match

Input
2023-03-22; UTC+8 calendar date
Production output
2023-2-1 · leap=true
Independent reference and scope

2023-2-1 · leap=true

https://data.weather.gov.hk/weatherAPI/hko_data/calendar/nongli_calendar_2023.csv

Expand raw machine fields
{
  "id": "L02",
  "category": "lunar-calendar",
  "input": "2023-03-22; UTC+8 calendar date",
  "actual": {
    "year": 2023,
    "month": 2,
    "day": 1,
    "isLeapMonth": true
  },
  "reference": {
    "expected": {
      "year": 2023,
      "month": 2,
      "day": 1,
      "isLeapMonth": true
    },
    "scope": "civil calendar conversion only; not Ziwei leap-month chart convention",
    "source": "https://data.weather.gov.hk/weatherAPI/hko_data/calendar/nongli_calendar_2023.csv"
  },
  "status": "reference-match"
}

L03 · Declared reference fields match

Input
2023-04-19; UTC+8 calendar date
Production output
2023-2-29 · leap=true
Independent reference and scope

2023-2-29 · leap=true

https://data.weather.gov.hk/weatherAPI/hko_data/calendar/nongli_calendar_2023.csv

Expand raw machine fields
{
  "id": "L03",
  "category": "lunar-calendar",
  "input": "2023-04-19; UTC+8 calendar date",
  "actual": {
    "year": 2023,
    "month": 2,
    "day": 29,
    "isLeapMonth": true
  },
  "reference": {
    "expected": {
      "year": 2023,
      "month": 2,
      "day": 29,
      "isLeapMonth": true
    },
    "scope": "civil calendar conversion only; not Ziwei leap-month chart convention",
    "source": "https://data.weather.gov.hk/weatherAPI/hko_data/calendar/nongli_calendar_2023.csv"
  },
  "status": "reference-match"
}

L04 · Declared reference fields match

Input
2023-04-20; UTC+8 calendar date
Production output
2023-3-1 · leap=false
Independent reference and scope

2023-3-1 · leap=false

https://data.weather.gov.hk/weatherAPI/hko_data/calendar/nongli_calendar_2023.csv

Expand raw machine fields
{
  "id": "L04",
  "category": "lunar-calendar",
  "input": "2023-04-20; UTC+8 calendar date",
  "actual": {
    "year": 2023,
    "month": 3,
    "day": 1,
    "isLeapMonth": false
  },
  "reference": {
    "expected": {
      "year": 2023,
      "month": 3,
      "day": 1,
      "isLeapMonth": false
    },
    "scope": "civil calendar conversion only; not Ziwei leap-month chart convention",
    "source": "https://data.weather.gov.hk/weatherAPI/hko_data/calendar/nongli_calendar_2023.csv"
  },
  "status": "reference-match"
}

L05 · Declared reference fields match

Input
2024-02-09; UTC+8 calendar date
Production output
2023-12-30 · leap=false
Independent reference and scope

2023-12-30 · leap=false

https://data.weather.gov.hk/weatherAPI/hko_data/calendar/nongli_calendar_2024.csv

Expand raw machine fields
{
  "id": "L05",
  "category": "lunar-calendar",
  "input": "2024-02-09; UTC+8 calendar date",
  "actual": {
    "year": 2023,
    "month": 12,
    "day": 30,
    "isLeapMonth": false
  },
  "reference": {
    "expected": {
      "year": 2023,
      "month": 12,
      "day": 30,
      "isLeapMonth": false
    },
    "scope": "civil calendar conversion only; not Ziwei leap-month chart convention",
    "source": "https://data.weather.gov.hk/weatherAPI/hko_data/calendar/nongli_calendar_2024.csv"
  },
  "status": "reference-match"
}

L06 · Declared reference fields match

Input
2024-02-10; UTC+8 calendar date
Production output
2024-1-1 · leap=false
Independent reference and scope

2024-1-1 · leap=false

https://data.weather.gov.hk/weatherAPI/hko_data/calendar/nongli_calendar_2024.csv

Expand raw machine fields
{
  "id": "L06",
  "category": "lunar-calendar",
  "input": "2024-02-10; UTC+8 calendar date",
  "actual": {
    "year": 2024,
    "month": 1,
    "day": 1,
    "isLeapMonth": false
  },
  "reference": {
    "expected": {
      "year": 2024,
      "month": 1,
      "day": 1,
      "isLeapMonth": false
    },
    "scope": "civil calendar conversion only; not Ziwei leap-month chart convention",
    "source": "https://data.weather.gov.hk/weatherAPI/hko_data/calendar/nongli_calendar_2024.csv"
  },
  "status": "reference-match"
}

Time basis and date rollover (6)

T01 · Two approximations compared; no accuracy pass

Input
2024-1-1 0:05 UTC+8, 116.4°
Production output
2023-12-31 23:47 · Δday=-1 · Δmin=-18 · 子
Independent reference and scope

NOAA Δmin=-17.08 · Difference (minutes)=-0.92

https://gml.noaa.gov/grad/solcalc/solareqns.PDF

Expand raw machine fields
{
  "id": "T01",
  "category": "time-basis",
  "input": {
    "year": 2024,
    "month": 1,
    "day": 1,
    "hour": 0,
    "minute": 5,
    "longitude": 116.4,
    "location": "synthetic teaching input"
  },
  "actual": {
    "input": {
      "date": "2024-01-01",
      "time": "00:05",
      "location": "synthetic teaching input",
      "longitude": 116.4
    },
    "correction": {
      "longitudeCorrection": -14,
      "equationOfTimeCorrection": -4,
      "totalCorrection": -18
    },
    "result": {
      "clockTime": "00:05",
      "trueSolarTime": "23:47",
      "trueSolarDate": "2023-12-31",
      "dayOffset": -1,
      "shichen": "子",
      "shichenRange": "23:00-01:00"
    },
    "lunarInfo": {
      "lunarDate": "2023年11月20日",
      "yearGanZhi": "癸卯"
    },
    "solarTermInfo": {
      "current": "",
      "next": "小寒"
    }
  },
  "reference": {
    "differenceMinutes": -0.92,
    "noaaApproximateOffsetMinutes": -17.08,
    "scope": "comparison of two approximations; no accuracy pass; all inputs deliberately UTC+8, including west longitude",
    "source": "https://gml.noaa.gov/grad/solcalc/solareqns.PDF",
    "utcOffsetHours": 8
  },
  "status": "approximation-compared"
}

T02 · Two approximations compared; no accuracy pass

Input
2024-1-1 0:05 UTC+8, 104.06°
Production output
2023-12-31 22:57 · Δday=-1 · Δmin=-68 · 亥
Independent reference and scope

NOAA Δmin=-66.44 · Difference (minutes)=-1.56

https://gml.noaa.gov/grad/solcalc/solareqns.PDF

Expand raw machine fields
{
  "id": "T02",
  "category": "time-basis",
  "input": {
    "year": 2024,
    "month": 1,
    "day": 1,
    "hour": 0,
    "minute": 5,
    "longitude": 104.06,
    "location": "synthetic teaching input"
  },
  "actual": {
    "input": {
      "date": "2024-01-01",
      "time": "00:05",
      "location": "synthetic teaching input",
      "longitude": 104.06
    },
    "correction": {
      "longitudeCorrection": -64,
      "equationOfTimeCorrection": -4,
      "totalCorrection": -68
    },
    "result": {
      "clockTime": "00:05",
      "trueSolarTime": "22:57",
      "trueSolarDate": "2023-12-31",
      "dayOffset": -1,
      "shichen": "亥",
      "shichenRange": "21:00-23:00"
    },
    "lunarInfo": {
      "lunarDate": "2023年11月20日",
      "yearGanZhi": "癸卯"
    },
    "solarTermInfo": {
      "current": "",
      "next": "小寒"
    }
  },
  "reference": {
    "differenceMinutes": -1.56,
    "noaaApproximateOffsetMinutes": -66.44,
    "scope": "comparison of two approximations; no accuracy pass; all inputs deliberately UTC+8, including west longitude",
    "source": "https://gml.noaa.gov/grad/solcalc/solareqns.PDF",
    "utcOffsetHours": 8
  },
  "status": "approximation-compared"
}

T03 · Two approximations compared; no accuracy pass

Input
2024-11-3 23:55 UTC+8, 120°
Production output
2024-11-04 00:11 · Δday=1 · Δmin=16 · 子
Independent reference and scope

NOAA Δmin=16.35 · Difference (minutes)=-0.35

https://gml.noaa.gov/grad/solcalc/solareqns.PDF

Expand raw machine fields
{
  "id": "T03",
  "category": "time-basis",
  "input": {
    "year": 2024,
    "month": 11,
    "day": 3,
    "hour": 23,
    "minute": 55,
    "longitude": 120,
    "location": "synthetic teaching input"
  },
  "actual": {
    "input": {
      "date": "2024-11-03",
      "time": "23:55",
      "location": "synthetic teaching input",
      "longitude": 120
    },
    "correction": {
      "longitudeCorrection": 0,
      "equationOfTimeCorrection": 16,
      "totalCorrection": 16
    },
    "result": {
      "clockTime": "23:55",
      "trueSolarTime": "00:11",
      "trueSolarDate": "2024-11-04",
      "dayOffset": 1,
      "shichen": "子",
      "shichenRange": "23:00-01:00"
    },
    "lunarInfo": {
      "lunarDate": "2024年10月3日",
      "yearGanZhi": "甲辰"
    },
    "solarTermInfo": {
      "current": "",
      "next": "立冬"
    }
  },
  "reference": {
    "differenceMinutes": -0.35,
    "noaaApproximateOffsetMinutes": 16.35,
    "scope": "comparison of two approximations; no accuracy pass; all inputs deliberately UTC+8, including west longitude",
    "source": "https://gml.noaa.gov/grad/solcalc/solareqns.PDF",
    "utcOffsetHours": 8
  },
  "status": "approximation-compared"
}

T04 · Two approximations compared; no accuracy pass

Input
2024-11-3 23:55 UTC+8, 135°
Production output
2024-11-04 01:11 · Δday=1 · Δmin=76 · 丑
Independent reference and scope

NOAA Δmin=76.35 · Difference (minutes)=-0.35

https://gml.noaa.gov/grad/solcalc/solareqns.PDF

Expand raw machine fields
{
  "id": "T04",
  "category": "time-basis",
  "input": {
    "year": 2024,
    "month": 11,
    "day": 3,
    "hour": 23,
    "minute": 55,
    "longitude": 135,
    "location": "synthetic teaching input"
  },
  "actual": {
    "input": {
      "date": "2024-11-03",
      "time": "23:55",
      "location": "synthetic teaching input",
      "longitude": 135
    },
    "correction": {
      "longitudeCorrection": 60,
      "equationOfTimeCorrection": 16,
      "totalCorrection": 76
    },
    "result": {
      "clockTime": "23:55",
      "trueSolarTime": "01:11",
      "trueSolarDate": "2024-11-04",
      "dayOffset": 1,
      "shichen": "丑",
      "shichenRange": "01:00-03:00"
    },
    "lunarInfo": {
      "lunarDate": "2024年10月3日",
      "yearGanZhi": "甲辰"
    },
    "solarTermInfo": {
      "current": "",
      "next": "立冬"
    }
  },
  "reference": {
    "differenceMinutes": -0.35,
    "noaaApproximateOffsetMinutes": 76.35,
    "scope": "comparison of two approximations; no accuracy pass; all inputs deliberately UTC+8, including west longitude",
    "source": "https://gml.noaa.gov/grad/solcalc/solareqns.PDF",
    "utcOffsetHours": 8
  },
  "status": "approximation-compared"
}

T05 · Two approximations compared; no accuracy pass

Input
2024-6-15 12:00 UTC+8, 75.98°
Production output
2024-06-15 09:04 · Δday=0 · Δmin=-176 · 巳
Independent reference and scope

NOAA Δmin=-176.22 · Difference (minutes)=0.22

https://gml.noaa.gov/grad/solcalc/solareqns.PDF

Expand raw machine fields
{
  "id": "T05",
  "category": "time-basis",
  "input": {
    "year": 2024,
    "month": 6,
    "day": 15,
    "hour": 12,
    "minute": 0,
    "longitude": 75.98,
    "location": "synthetic teaching input"
  },
  "actual": {
    "input": {
      "date": "2024-06-15",
      "time": "12:00",
      "location": "synthetic teaching input",
      "longitude": 75.98
    },
    "correction": {
      "longitudeCorrection": -176,
      "equationOfTimeCorrection": 0,
      "totalCorrection": -176
    },
    "result": {
      "clockTime": "12:00",
      "trueSolarTime": "09:04",
      "trueSolarDate": "2024-06-15",
      "dayOffset": 0,
      "shichen": "巳",
      "shichenRange": "09:00-11:00"
    },
    "lunarInfo": {
      "lunarDate": "2024年5月10日",
      "yearGanZhi": "甲辰"
    },
    "solarTermInfo": {
      "current": "",
      "next": "夏至"
    }
  },
  "reference": {
    "differenceMinutes": 0.22,
    "noaaApproximateOffsetMinutes": -176.22,
    "scope": "comparison of two approximations; no accuracy pass; all inputs deliberately UTC+8, including west longitude",
    "source": "https://gml.noaa.gov/grad/solcalc/solareqns.PDF",
    "utcOffsetHours": 8
  },
  "status": "approximation-compared"
}

T06 · Two approximations compared; no accuracy pass

Input
2024-6-15 0:05 UTC+8, -74°
Production output
2024-06-14 11:09 · Δday=-1 · Δmin=-776 · 午
Independent reference and scope

NOAA Δmin=-776.04 · Difference (minutes)=0.04

https://gml.noaa.gov/grad/solcalc/solareqns.PDF

Expand raw machine fields
{
  "id": "T06",
  "category": "time-basis",
  "input": {
    "year": 2024,
    "month": 6,
    "day": 15,
    "hour": 0,
    "minute": 5,
    "longitude": -74,
    "location": "synthetic teaching input"
  },
  "actual": {
    "input": {
      "date": "2024-06-15",
      "time": "00:05",
      "location": "synthetic teaching input",
      "longitude": -74
    },
    "correction": {
      "longitudeCorrection": -776,
      "equationOfTimeCorrection": 0,
      "totalCorrection": -776
    },
    "result": {
      "clockTime": "00:05",
      "trueSolarTime": "11:09",
      "trueSolarDate": "2024-06-14",
      "dayOffset": -1,
      "shichen": "午",
      "shichenRange": "11:00-13:00"
    },
    "lunarInfo": {
      "lunarDate": "2024年5月10日",
      "yearGanZhi": "甲辰"
    },
    "solarTermInfo": {
      "current": "",
      "next": "夏至"
    }
  },
  "reference": {
    "differenceMinutes": 0.04,
    "noaaApproximateOffsetMinutes": -776.04,
    "scope": "comparison of two approximations; no accuracy pass; all inputs deliberately UTC+8, including west longitude",
    "source": "https://gml.noaa.gov/grad/solcalc/solareqns.PDF",
    "utcOffsetHours": 8
  },
  "status": "approximation-compared"
}

Continue your task

Check solar time and rolloverTroubleshoot chart differences

Sources and further checks

Taiwan CWA 2024 Almanac: 24 solar terms (UTC+8), printed page 4HKO 2023 calendar CSVHKO 2024 calendar CSVNOAA independent solar-time approximation

Maintained by the Fateverse project content team. This page explains the current calculation rules and traditional sources; it has not received an independently named professional review. Updated 27 October 2026. Compare the linked calculation records before relying on a boundary case.