feat: 引入可切换星历模型并扩展天象观测链路

- 新增半解析、旧模型、自定义与多源堆叠星历实例，提供 Context、Instance、SPK 读取及状态与视位置计算
- 统一太阳、月球和行星实例接口，扩展黄经穿越、留、相位、最近角距、偕日可见、任意高度升落、轨道节点及凌日等天象查询
- 完善日月食、月掩与凌日的月缘剖面、有限盘面接触、站心修正、局地可见性、全球路径和地图输出
- 新增 SVG、GeoJSON、KML 天象输出及凌日、月掩和月缘地形相关缓存与几何求解
- 新增恒星星表导入与查询，支持 CSV、Hipparcos、BSC5、Stellarium 等格式及名称、交叉标识、锥面检索和星等过滤
- 补充 IAU 2006、地球定向、折射消光、大气观测、轨道传播及半解析行星/月球数据支持
- 将默认未来民用时标切换为 TimeScaleLeapHour，更新 2027–2400 农历速查表、中文日期解析和时区边界处理
- 增加事件基线、跨模型回归、几何边界、月缘地形和输出契约测试，完善中英文手册、示例资源、NOTICE 与忽略规则

lite/internal/common.go

@@ -5,8 +5,6 @@ import (
 	"math"
 
 	. "b612.me/astro/tools"
-
-	"b612.me/astro/basic"
 )
 
 const (
@@ -40,7 +38,7 @@ func EclipticToEquatorial(jde, lo, bo float64) (float64, float64) {
 }
 
 func HorizontalCoordinates(ra, dec, jd, lon, lat float64) (float64, float64, float64) {
-	lst := Limit360(MeanSiderealTime(basic.UTC2UT1(jd)) + lon)
+	lst := Limit360(MeanSiderealTime(UTC2UT1(jd)) + lon)
 	hourAngle := Limit360(lst - ra)
 	altitude := ArcSin(clampUnit(Sin(lat)*Sin(dec) + Cos(lat)*Cos(dec)*Cos(hourAngle)))
 
@@ -65,7 +63,7 @@ func TopocentricRaDec(ra, dec, observerLat, observerLon, jd, distanceEarthRadii,
 	rhoCos := math.Cos(u) + heightMeters/6378140.0*Cos(observerLat)
 	parallax := math.Asin(1.0 / distanceEarthRadii)
 
-	hourAngle := (Limit360(MeanSiderealTime(basic.UTC2UT1(jd)) + observerLon - ra)) * math.Pi / 180.0
+	hourAngle := (Limit360(MeanSiderealTime(UTC2UT1(jd)) + observerLon - ra)) * math.Pi / 180.0
 	decRad := dec * math.Pi / 180.0
 
 	numerator := -rhoCos * math.Sin(parallax) * math.Sin(hourAngle)

lite/internal/horizon.go

@@ -0,0 +1,28 @@
+package internal
+
+import "math"
+
+const (
+	earthEquatorialRadius = 6378137.0
+	earthPolarRadius      = 6356752.3
+)
+
+// HeightDegreeByLat 高度对应地平线下角 / horizon dip at latitude.
+func HeightDegreeByLat(height, lat float64) float64 {
+	radius := geocentricRadius(lat)
+	return math.Acos(radius/(radius+height)) * 180 / math.Pi
+}
+
+func geocentricRadius(lat float64) float64 {
+	cosLat := math.Cos(lat * math.Pi / 180)
+	sinLat := math.Sin(lat * math.Pi / 180)
+	a := earthEquatorialRadius * earthEquatorialRadius * cosLat
+	a *= a
+	b := earthPolarRadius * earthPolarRadius * sinLat
+	b *= b
+	c := earthEquatorialRadius * cosLat
+	c *= c
+	d := earthPolarRadius * sinLat
+	d *= d
+	return math.Sqrt((a + b) / (c + d))
+}

lite/internal/horizon_test.go

@@ -0,0 +1,18 @@
+package internal
+
+import (
+	"math"
+	"testing"
+
+	"b612.me/astro/basic"
+)
+
+func TestHeightDegreeByLatTakesDegrees(t *testing.T) {
+	for _, lat := range []float64{0, 30, 60, -45, 89} {
+		got := HeightDegreeByLat(10000, lat)
+		want := basic.HeightDegreeByLat(10000, lat)
+		if math.Abs(got-want) > 1e-9 {
+			t.Fatalf("lat %v: lite %.9f, basic %.9f", lat, got, want)
+		}
+	}
+}

lite/internal/refraction.go

@@ -0,0 +1,25 @@
+package internal
+
+import "math"
+
+const (
+	refractionStandardPressureHPa  = 1010.0
+	refractionStandardTemperatureK = 283.15
+	refractionAbsoluteZeroC        = -273.15
+	refractionLowerLimitAltitude   = -5.0
+	refractionUpperLimitAltitude   = 90.0
+)
+
+// RefractionFromTrueAltitude 真高度到视高度的折射修正 / true-to-apparent altitude refraction.
+func RefractionFromTrueAltitude(trueAltitude, pressureHPa, temperatureC float64) float64 {
+	if !validRefractionInputs(trueAltitude, pressureHPa, temperatureC) || trueAltitude <= refractionLowerLimitAltitude || trueAltitude >= refractionUpperLimitAltitude {
+		return 0
+	}
+	angle := (trueAltitude + 10.3/(trueAltitude+5.11)) * math.Pi / 180
+	scale := pressureHPa / refractionStandardPressureHPa * refractionStandardTemperatureK / (temperatureC - refractionAbsoluteZeroC)
+	return scale * (1.02 / math.Tan(angle)) / 60
+}
+
+func validRefractionInputs(altitude, pressureHPa, temperatureC float64) bool {
+	return !(math.IsNaN(altitude) || math.IsInf(altitude, 0) || math.IsNaN(pressureHPa) || math.IsInf(pressureHPa, 0) || pressureHPa <= 0 || math.IsNaN(temperatureC) || math.IsInf(temperatureC, 0) || temperatureC <= refractionAbsoluteZeroC)
+}

lite/internal/time.go

@@ -0,0 +1,114 @@
+package internal
+
+import (
+	"errors"
+	"math"
+	"time"
+)
+
+// ErrInvalidCivilDate 日期非法 / invalid civil date.
+var ErrInvalidCivilDate = errors.New("invalid civil date")
+
+// Date2JD 日期转儒略日 / Julian day from a civil time.
+func Date2JD(date time.Time) float64 {
+	day := float64(date.Day()) + float64(date.Hour())/24.0 + float64(date.Minute())/1440.0 + float64(date.Second())/86400.0 + float64(date.Nanosecond())/86400000000000.0
+	return JDCalc(date.Year(), int(date.Month()), day)
+}
+
+// JDCalc 由公历年月日计算儒略日 / Julian day from a civil date.
+func JDCalc(year, month int, day float64) float64 {
+	if !validCivilDate(year, month, day) {
+		return math.NaN()
+	}
+	effectiveYear, effectiveMonth, effectiveDay := year, month, int(math.Floor(day))
+	if month == 1 || month == 2 {
+		year--
+		month += 12
+	}
+	correction := 0
+	if effectiveYear > 1582 || (effectiveYear == 1582 && (effectiveMonth > 10 || (effectiveMonth == 10 && effectiveDay >= 15))) {
+		century := int(year / 100)
+		correction = 2 - century + int(century/4)
+	}
+	return math.Floor(365.25*(float64(year)+4716.0)) + math.Floor(30.6001*float64(month+1)) + day + float64(correction) - 1524.5
+}
+
+func validCivilDate(year, month int, day float64) bool {
+	if math.IsNaN(day) || math.IsInf(day, 0) || month < 1 || month > 12 || day < 1 {
+		return false
+	}
+	dayInt := int(math.Floor(day))
+	if dayInt > daysInCivilMonth(year, month) {
+		return false
+	}
+	return !(year == 1582 && month == 10 && day >= 5 && day < 15)
+}
+
+func daysInCivilMonth(year, month int) int {
+	switch month {
+	case 1, 3, 5, 7, 8, 10, 12:
+		return 31
+	case 4, 6, 9, 11:
+		return 30
+	case 2:
+		if isCivilLeapYear(year, month, 1) {
+			return 29
+		}
+		return 28
+	default:
+		return 0
+	}
+}
+
+func isCivilLeapYear(year, month int, day float64) bool {
+	if year < 1582 || (year == 1582 && (month < 10 || (month == 10 && day <= 4))) {
+		return year%4 == 0
+	}
+	if year%400 == 0 {
+		return true
+	}
+	if year%100 == 0 {
+		return false
+	}
+	return year%4 == 0
+}
+
+// JD2DateByZone 儒略日转目标时区日期 / convert a Julian day to a target timezone.
+func JD2DateByZone(jd float64, tz *time.Location, byZone bool) time.Time {
+	jd += 0.5
+	z := float64(int(jd))
+	fraction := jd - z
+	a := z
+	if z >= 2299161.0 {
+		alpha := math.Floor((z - 1867216.25) / 36524.25)
+		a = z + 1 + alpha - math.Floor(alpha/4)
+	}
+	b := a + 1524
+	c := math.Floor((b - 122.1) / 365.25)
+	d := math.Floor(365.25 * c)
+	e := math.Floor((b - d) / 30.6001)
+	days := b - d - math.Floor(30.6001*e) + fraction
+	month := e - 1
+	if e >= 14 {
+		month = e - 13
+	}
+	year := c - 4716
+	if month <= 2 {
+		year = c - 4715
+	}
+	seconds := (days - math.Floor(days)) * 86400
+	day := math.Floor(days)
+	date := time.Date(int(year), time.Month(int(month)), int(day), 0, 0, 0, 0, time.UTC).
+		Add(time.Duration(int64(1000000000 * seconds)))
+	if !byZone {
+		return date.In(tz)
+	}
+	y, m, dayInt := date.Date()
+	h, minute, second := date.Clock()
+	return time.Date(y, m, dayInt, h, minute, second, date.Nanosecond(), tz)
+}
+
+// UTC2UT1 轻量民用时转世界时，忽略 DUT1（|UT1−UTC| < 0.9 s） / lightweight UTC to UT1, DUT1 ignored.
+func UTC2UT1(jd float64) float64 {
+	return jd
+}

lite/internal/time_test.go

@@ -0,0 +1,39 @@
+package internal
+
+import (
+	"math"
+	"testing"
+	"time"
+)
+
+func TestDateJulianRoundTrip(t *testing.T) {
+	cases := []struct {
+		date time.Time
+		jd   float64
+	}{
+		{time.Date(2026, 10, 6, 8, 30, 15, 123000000, time.UTC), 2461319.8543417014},
+		{time.Date(1582, 10, 4, 0, 0, 0, 0, time.UTC), 2299159.5},
+		{time.Date(1582, 10, 15, 0, 0, 0, 0, time.UTC), 2299160.5},
+	}
+	for _, tc := range cases {
+		if got := Date2JD(tc.date); math.Abs(got-tc.jd) > 1e-9 {
+			t.Fatalf("Date2JD(%s) = %.12f, want %.12f", tc.date, got, tc.jd)
+		}
+	}
+}
+
+func TestJD2DateByZone(t *testing.T) {
+	zone := time.FixedZone("CST", 8*3600)
+	got := JD2DateByZone(2461320.5, zone, false)
+	want := time.Date(2026, 10, 7, 8, 0, 0, 0, zone)
+	if !got.Equal(want) {
+		t.Fatalf("JD2DateByZone = %s, want %s", got, want)
+	}
+}
+
+func TestUTC2UT1IgnoresDUT1(t *testing.T) {
+	jd := 2461320.5
+	if got := UTC2UT1(jd); got != jd {
+		t.Fatalf("UTC2UT1 = %.12f, want %.12f", got, jd)
+	}
+}

lite/moon/moon.go

@@ -6,7 +6,6 @@ import (
 	"math"
 	"time"
 
-	"b612.me/astro/basic"
 	lite "b612.me/astro/lite/internal"
 	. "b612.me/astro/tools"
 )
@@ -19,50 +18,50 @@ var (
 
 // TrueLo 轻量真黄经 / lightweight true ecliptic longitude.
 func TrueLo(date time.Time) float64 {
-	return lite.MoonGeocentric(basic.Date2JD(date.UTC())).Longitude
+	return lite.MoonGeocentric(lite.Date2JD(date.UTC())).Longitude
 }
 
 // TrueBo 轻量真黄纬 / lightweight true ecliptic latitude.
 func TrueBo(date time.Time) float64 {
-	return lite.MoonGeocentric(basic.Date2JD(date.UTC())).Latitude
+	return lite.MoonGeocentric(lite.Date2JD(date.UTC())).Latitude
 }
 
 // TrueRa 轻量真赤经 / lightweight true right ascension.
 func TrueRa(date time.Time) float64 {
-	return lite.MoonGeocentric(basic.Date2JD(date.UTC())).RightAscension
+	return lite.MoonGeocentric(lite.Date2JD(date.UTC())).RightAscension
 }
 
 // TrueDec 轻量真赤纬 / lightweight true declination.
 func TrueDec(date time.Time) float64 {
-	return lite.MoonGeocentric(basic.Date2JD(date.UTC())).Declination
+	return lite.MoonGeocentric(lite.Date2JD(date.UTC())).Declination
 }
 
 // TrueRaDec 轻量真赤经、真赤纬 / lightweight true right ascension and declination.
 func TrueRaDec(date time.Time) (float64, float64) {
-	state := lite.MoonGeocentric(basic.Date2JD(date.UTC()))
+	state := lite.MoonGeocentric(lite.Date2JD(date.UTC()))
 	return state.RightAscension, state.Declination
 }
 
 // ApparentRa 轻量站心视赤经 / lightweight topocentric apparent right ascension.
 func ApparentRa(date time.Time, lon, lat float64) float64 {
-	state := lite.MoonTopocentric(basic.Date2JD(date.UTC()), lon, lat, 0)
+	state := lite.MoonTopocentric(lite.Date2JD(date.UTC()), lon, lat, 0)
 	return state.RightAscension
 }
 
 // ApparentDec 轻量站心视赤纬 / lightweight topocentric apparent declination.
 func ApparentDec(date time.Time, lon, lat float64) float64 {
-	state := lite.MoonTopocentric(basic.Date2JD(date.UTC()), lon, lat, 0)
+	state := lite.MoonTopocentric(lite.Date2JD(date.UTC()), lon, lat, 0)
 	return state.Declination
 }
 
 // ApparentRaDec 轻量站心视赤经、视赤纬 / lightweight topocentric apparent right ascension and declination.
 func ApparentRaDec(date time.Time, lon, lat float64) (float64, float64) {
-	state := lite.MoonTopocentric(basic.Date2JD(date.UTC()), lon, lat, 0)
+	state := lite.MoonTopocentric(lite.Date2JD(date.UTC()), lon, lat, 0)
 	return state.RightAscension, state.Declination
 }
 
 func topocentricHorizontal(date time.Time, lon, lat float64) (altitude, azimuth, hourAngle float64) {
-	jd := basic.Date2JD(date.UTC())
+	jd := lite.Date2JD(date.UTC())
 	state := lite.MoonTopocentric(jd, lon, lat, 0)
 	return lite.HorizontalCoordinates(state.RightAscension, state.Declination, jd, lon, lat)
 }
@@ -93,7 +92,7 @@ func Zenith(date time.Time, lon, lat float64) float64 {
 
 // SunMoonLoDiff 轻量日月黄经差 / lightweight Moon-Sun ecliptic-longitude difference.
 func SunMoonLoDiff(date time.Time) float64 {
-	jdUTC := basic.Date2JD(date.UTC())
+	jdUTC := lite.Date2JD(date.UTC())
 	return Limit360(lite.MoonGeocentric(jdUTC).Longitude - lite.SunApparentLo(jdUTC))
 }
 
@@ -129,11 +128,11 @@ func SetTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, er
 
 func riseSetTime(date time.Time, lon, lat, height float64, aero, isRise bool) (time.Time, error) {
 	localMidnight := time.Date(date.Year(), date.Month(), date.Day(), 0, 0, 0, 0, date.Location())
-	localJD := basic.Date2JD(localMidnight)
+	localJD := lite.Date2JD(localMidnight)
 	_, offset := localMidnight.Zone()
 	timezone := float64(offset) / 3600.0
 
-	horizonDip := basic.HeightDegreeByLat(height, lat)
+	horizonDip := lite.HeightDegreeByLat(height, lat)
 
 	altitudeFn := func(localJD float64) float64 {
 		utcJD := localJD - timezone/24.0
@@ -141,7 +140,7 @@ func riseSetTime(date time.Time, lon, lat, height float64, aero, isRise bool) (t
 		altitude, _, _ := lite.HorizontalCoordinates(state.RightAscension, state.Declination, utcJD, lon, lat)
 		residual := altitude + horizonDip
 		if aero {
-			residual += basic.RefractionFromTrueAltitude(altitude, 1010, 10)
+			residual += lite.RefractionFromTrueAltitude(altitude, 1010, 10)
 			residual += liteMoonSemidiameterDegrees(state.DistanceEarthRadii)
 		}
 		return residual
@@ -160,7 +159,7 @@ func riseSetTime(date time.Time, lon, lat, height float64, aero, isRise bool) (t
 			return time.Time{}, err
 		}
 	}
-	return basic.JD2DateByZone(eventJD-timezone/24, date.Location(), false), nil
+	return lite.JD2DateByZone(eventJD-timezone/24, date.Location(), false), nil
 }
 
 func liteMoonSemidiameterDegrees(distanceEarthRadii float64) float64 {

lite/sun/sun.go

@@ -6,7 +6,6 @@ import (
 	"math"
 	"time"
 
-	"b612.me/astro/basic"
 	lite "b612.me/astro/lite/internal"
 )
 
@@ -17,68 +16,68 @@ var (
 
 // TrueLo 轻量真黄经 / lightweight true ecliptic longitude.
 func TrueLo(date time.Time) float64 {
-	return lite.SunTrueLo(basic.Date2JD(date.UTC()))
+	return lite.SunTrueLo(lite.Date2JD(date.UTC()))
 }
 
 // ApparentLo 轻量视黄经 / lightweight apparent ecliptic longitude.
 func ApparentLo(date time.Time) float64 {
-	return lite.SunApparentLo(basic.Date2JD(date.UTC()))
+	return lite.SunApparentLo(lite.Date2JD(date.UTC()))
 }
 
 // Distance 轻量日地距离 / lightweight Sun-Earth distance in AU.
 func Distance(date time.Time) float64 {
-	return lite.SunDistanceAU(basic.Date2JD(date.UTC()))
+	return lite.SunDistanceAU(lite.Date2JD(date.UTC()))
 }
 
 // TrueRa 轻量真赤经 / lightweight true right ascension.
 func TrueRa(date time.Time) float64 {
-	ra, _ := lite.SunTrueRaDec(basic.Date2JD(date.UTC()))
+	ra, _ := lite.SunTrueRaDec(lite.Date2JD(date.UTC()))
 	return ra
 }
 
 // TrueDec 轻量真赤纬 / lightweight true declination.
 func TrueDec(date time.Time) float64 {
-	_, dec := lite.SunTrueRaDec(basic.Date2JD(date.UTC()))
+	_, dec := lite.SunTrueRaDec(lite.Date2JD(date.UTC()))
 	return dec
 }
 
 // TrueRaDec 轻量真赤经、真赤纬 / lightweight true right ascension and declination.
 func TrueRaDec(date time.Time) (float64, float64) {
-	return lite.SunTrueRaDec(basic.Date2JD(date.UTC()))
+	return lite.SunTrueRaDec(lite.Date2JD(date.UTC()))
 }
 
 // ApparentRa 轻量视赤经 / lightweight apparent right ascension.
 func ApparentRa(date time.Time) float64 {
-	ra, _ := lite.SunApparentRaDec(basic.Date2JD(date.UTC()))
+	ra, _ := lite.SunApparentRaDec(lite.Date2JD(date.UTC()))
 	return ra
 }
 
 // ApparentDec 轻量视赤纬 / lightweight apparent declination.
 func ApparentDec(date time.Time) float64 {
-	_, dec := lite.SunApparentRaDec(basic.Date2JD(date.UTC()))
+	_, dec := lite.SunApparentRaDec(lite.Date2JD(date.UTC()))
 	return dec
 }
 
 // ApparentRaDec 轻量视赤经、视赤纬 / lightweight apparent right ascension and declination.
 func ApparentRaDec(date time.Time) (float64, float64) {
-	return lite.SunApparentRaDec(basic.Date2JD(date.UTC()))
+	return lite.SunApparentRaDec(lite.Date2JD(date.UTC()))
 }
 
 // HourAngle 轻量时角 / lightweight hour angle.
 func HourAngle(date time.Time, lon, lat float64) float64 {
-	_, _, hourAngle := lite.HorizontalCoordinates(ApparentRa(date), ApparentDec(date), basic.Date2JD(date.UTC()), lon, lat)
+	_, _, hourAngle := lite.HorizontalCoordinates(ApparentRa(date), ApparentDec(date), lite.Date2JD(date.UTC()), lon, lat)
 	return hourAngle
 }
 
 // Azimuth 轻量方位角 / lightweight azimuth.
 func Azimuth(date time.Time, lon, lat float64) float64 {
-	_, azimuth, _ := lite.HorizontalCoordinates(ApparentRa(date), ApparentDec(date), basic.Date2JD(date.UTC()), lon, lat)
+	_, azimuth, _ := lite.HorizontalCoordinates(ApparentRa(date), ApparentDec(date), lite.Date2JD(date.UTC()), lon, lat)
 	return azimuth
 }
 
 // Altitude 轻量高度角 / lightweight altitude.
 func Altitude(date time.Time, lon, lat float64) float64 {
-	altitude, _, _ := lite.HorizontalCoordinates(ApparentRa(date), ApparentDec(date), basic.Date2JD(date.UTC()), lon, lat)
+	altitude, _, _ := lite.HorizontalCoordinates(ApparentRa(date), ApparentDec(date), lite.Date2JD(date.UTC()), lon, lat)
 	return altitude
 }
 
@@ -89,7 +88,7 @@ func Zenith(date time.Time, lon, lat float64) float64 {
 
 // RiseTime 轻量日出时刻 / lightweight sunrise time.
 func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
-	if result, err, handled := civiltime.Event(date, basic.ErrNotOnThisDate, func(d time.Time) (time.Time, error) {
+	if result, err, handled := civiltime.Event(date, lite.ErrNotOnThisDate, func(d time.Time) (time.Time, error) {
 		return RiseTime(d, lon, lat, height, aero)
 	}); handled {
 		return result, err
@@ -99,7 +98,7 @@ func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 
 // SetTime 轻量日落时刻 / lightweight sunset time.
 func SetTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
-	if result, err, handled := civiltime.Event(date, basic.ErrNotOnThisDate, func(d time.Time) (time.Time, error) {
+	if result, err, handled := civiltime.Event(date, lite.ErrNotOnThisDate, func(d time.Time) (time.Time, error) {
 		return SetTime(d, lon, lat, height, aero)
 	}); handled {
 		return result, err
@@ -109,11 +108,11 @@ func SetTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, er
 
 func riseSetTime(date time.Time, lon, lat, height float64, aero, isRise bool) (time.Time, error) {
 	localMidnight := time.Date(date.Year(), date.Month(), date.Day(), 0, 0, 0, 0, date.Location())
-	localJD := basic.Date2JD(localMidnight)
+	localJD := lite.Date2JD(localMidnight)
 	_, offset := localMidnight.Zone()
 	timezone := float64(offset) / 3600.0
 
-	horizonDip := basic.HeightDegreeByLat(height, lat)
+	horizonDip := lite.HeightDegreeByLat(height, lat)
 
 	altitudeFn := func(localJD float64) float64 {
 		utcJD := localJD - timezone/24.0
@@ -121,7 +120,7 @@ func riseSetTime(date time.Time, lon, lat, height float64, aero, isRise bool) (t
 		altitude, _, _ := lite.HorizontalCoordinates(ra, dec, utcJD, lon, lat)
 		residual := altitude + horizonDip
 		if aero {
-			residual += basic.RefractionFromTrueAltitude(altitude, 1010, 10)
+			residual += lite.RefractionFromTrueAltitude(altitude, 1010, 10)
 			residual += liteSunSemidiameterDegrees(lite.SunDistanceAU(utcJD))
 		}
 		return residual
@@ -138,7 +137,7 @@ func riseSetTime(date time.Time, lon, lat, height float64, aero, isRise bool) (t
 			return time.Time{}, err
 		}
 	}
-	return basic.JD2DateByZone(eventJD-timezone/24, date.Location(), false), nil
+	return lite.JD2DateByZone(eventJD-timezone/24, date.Location(), false), nil
 }
 
 func liteSunSemidiameterDegrees(distanceAU float64) float64 {