diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..723ef36
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+.idea
\ No newline at end of file
diff --git a/.idea/.gitignore b/.idea/.gitignore
deleted file mode 100644
index 183738e..0000000
--- a/.idea/.gitignore
+++ /dev/null
@@ -1,8 +0,0 @@
-# 默认忽略的文件
-/shelf/
-/workspace.xml
-# 数据源本地存储已忽略文件
-/../../../../../../:\gocode\src\b612.me\astro\.idea/dataSources/
-/dataSources.local.xml
-# 基于编辑器的 HTTP 客户端请求
-/httpRequests/
diff --git a/.idea/astro.iml b/.idea/astro.iml
deleted file mode 100644
index 5e764c4..0000000
--- a/.idea/astro.iml
+++ /dev/null
@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<module type="WEB_MODULE" version="4">
-  <component name="Go" enabled="true" />
-  <component name="NewModuleRootManager">
-    <content url="file://$MODULE_DIR$" />
-    <orderEntry type="inheritedJdk" />
-    <orderEntry type="sourceFolder" forTests="false" />
-  </component>
-</module>
\ No newline at end of file
diff --git a/.idea/modules.xml b/.idea/modules.xml
deleted file mode 100644
index e85cb08..0000000
--- a/.idea/modules.xml
+++ /dev/null
@@ -1,8 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="ProjectModuleManager">
-    <modules>
-      <module fileurl="file://$PROJECT_DIR$/.idea/astro.iml" filepath="$PROJECT_DIR$/.idea/astro.iml" />
-    </modules>
-  </component>
-</project>
\ No newline at end of file
diff --git a/.idea/vcs.xml b/.idea/vcs.xml
deleted file mode 100644
index 94a25f7..0000000
--- a/.idea/vcs.xml
+++ /dev/null
@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="VcsDirectoryMappings">
-    <mapping directory="$PROJECT_DIR$" vcs="Git" />
-  </component>
-</project>
\ No newline at end of file
diff --git a/basic/all_test.go b/basic/all_test.go
index bfbe1a5..63426b6 100644
--- a/basic/all_test.go
+++ b/basic/all_test.go
@@ -26,7 +26,7 @@ func show() {
 	fmt.Println("当前太阳星座：", WhichCst(ra, dec, jde))
 	fmt.Println("当前黄赤交角：", EclipticObliquity(jde-8.0/24.0, true))
 	fmt.Println("当前日出：", JDE2Date(GetSunRiseTime(jde, 115, 32, 8, 1, 10)))
-	fmt.Println("当前日落：", JDE2Date(GetSunDownTime(jde, 115, 32, 8, 1, 10)))
+	fmt.Println("当前日落：", JDE2Date(GetSunSetTime(jde, 115, 32, 8, 1, 10)))
 	fmt.Println("当前晨影 -6：", JDE2Date(GetAsaTime(jde, 115, 32, 8, -6)))
 	fmt.Println("当前晨影 -12：", JDE2Date(GetAsaTime(jde, 115, 32, 8, -12)))
 	fmt.Println("当前昏影 -6：", JDE2Date(GetBanTime(jde, 115, 32, 8, -6)))
diff --git a/basic/sun.go b/basic/sun.go
index abcdde4..0623903 100644
--- a/basic/sun.go
+++ b/basic/sun.go
@@ -551,7 +551,7 @@ func GetSunRiseTime(JD, Lon, Lat, TZ, ZS, HEI float64) float64 {
 	}
 	return JD1 - ntz/24 + TZ/24
 }
-func GetSunDownTime(JD, Lon, Lat, TZ, ZS, HEI float64) float64 {
+func GetSunSetTime(JD, Lon, Lat, TZ, ZS, HEI float64) float64 {
 	var An float64
 	JD = math.Floor(JD) + 1.5
 	ntz := math.Round(Lon / 15)
diff --git a/basic/sun_test.go b/basic/sun_test.go
index 8d2353a..1e0ef39 100644
--- a/basic/sun_test.go
+++ b/basic/sun_test.go
@@ -10,7 +10,7 @@ import (
 
 func Test_Jq(t *testing.T) {
 	data := GetJieqiLoops(2019, 24)
-	for i := 1; i < 25; i++ {
+	for i := 1; i < len(data); i++ {
 		fmt.Println(JDE2Date(data[i]))
 	}
 	//fmt.Println(JDE2Date(GetWHTime(2019, 10)))
@@ -144,7 +144,7 @@ func Test_SunRiseRound(t *testing.T) {
 func Test_SunDown(t *testing.T) {
 	jde := GetNowJDE()
 	for i := 10.0; i < 90.0; i += 0.3 {
-		fmt.Println(i, GetSunDownTime(jde, 115, float64(i), 8, 0, 0))
+		fmt.Println(i, GetSunSetTime(jde, 115, float64(i), 8, 0, 0))
 	}
 }
 
diff --git a/jupiter/jupiter.go b/jupiter/jupiter.go
index 2775320..6851c0e 100644
--- a/jupiter/jupiter.go
+++ b/jupiter/jupiter.go
@@ -10,7 +10,9 @@ import (
 
 var (
 	ERR_JUPITER_NEVER_RISE = errors.New("ERROR:极夜，木星今日永远在地平线下！")
-	ERR_JUPITER_NEVER_DOWN = errors.New("ERROR:极昼，木星今日永远在地平线上！")
+	ERR_JUPITER_NEVER_SET  = errors.New("ERROR:极昼，木星今日永远在地平线上！")
+	// ERR_JUPITER_NEVER_DOWN deprecated -- use ERR_JUPITER_NEVER_SET instead
+	ERR_JUPITER_NEVER_DOWN = ERR_JUPITER_NEVER_SET
 )
 
 // ApparentLo 视黄经
@@ -122,11 +124,12 @@ func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_JUPITER_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_JUPITER_NEVER_DOWN
+		err = ERR_JUPITER_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
 
+// deprecated -- use SetTime instead
 // DownTime 落下时间
 // date，取日期，时区忽略
 // lon，经度，东正西负
@@ -134,6 +137,16 @@ func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 // height，高度
 // aero，true时进行大气修正
 func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
+	return SetTime(date, lon, lat, height, aero)
+}
+
+// SetTime 落下时间
+// date，取日期，时区忽略
+// lon，经度，东正西负
+// lat，纬度，北正南负
+// height，高度
+// aero，true时进行大气修正
+func SetTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
 	var err error
 	var aeroFloat float64
 	if aero {
@@ -150,7 +163,7 @@ func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_JUPITER_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_JUPITER_NEVER_DOWN
+		err = ERR_JUPITER_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
@@ -205,7 +218,7 @@ func LastRetrogradeToPrograde(date time.Time) time.Time {
 }
 
 // NextRetrogradeToPrograde 上次留（逆转瞬）
-//// 返回上次逆转瞬留的时间
+// // 返回上次逆转瞬留的时间
 func NextRetrogradeToPrograde(date time.Time) time.Time {
 	jde := basic.TD2UT(basic.Date2JDE(date.UTC()), true)
 	return basic.JDE2DateByZone(basic.NextJupiterRetrogradeToPrograde(jde), date.Location(), false)
diff --git a/mars/mars.go b/mars/mars.go
index c65befb..e28fc25 100644
--- a/mars/mars.go
+++ b/mars/mars.go
@@ -10,7 +10,9 @@ import (
 
 var (
 	ERR_MARS_NEVER_RISE = errors.New("ERROR:极夜，火星今日永远在地平线下！")
-	ERR_MARS_NEVER_DOWN = errors.New("ERROR:极昼，火星今日永远在地平线上！")
+	ERR_MARS_NEVER_SET  = errors.New("ERROR:极昼，火星今日永远在地平线上！")
+	// ERR_MARS_NEVER_DOWN deprecated -- use ERR_MARS_NEVER_SET instead
+	ERR_MARS_NEVER_DOWN = ERR_MARS_NEVER_SET
 )
 
 // ApparentLo 视黄经
@@ -122,11 +124,12 @@ func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_MARS_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_MARS_NEVER_DOWN
+		err = ERR_MARS_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
 
+// deprecated -- use SetTime instead
 // DownTime 落下时间
 // date，取日期，时区忽略
 // lon，经度，东正西负
@@ -134,6 +137,16 @@ func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 // height，高度
 // aero，true时进行大气修正
 func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
+	return SetTime(date, lon, lat, height, aero)
+}
+
+// SetTime 落下时间
+// date，取日期，时区忽略
+// lon，经度，东正西负
+// lat，纬度，北正南负
+// height，高度
+// aero，true时进行大气修正
+func SetTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
 	var err error
 	var aeroFloat float64
 	if aero {
@@ -150,7 +163,7 @@ func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_MARS_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_MARS_NEVER_DOWN
+		err = ERR_MARS_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
@@ -205,7 +218,7 @@ func LastRetrogradeToPrograde(date time.Time) time.Time {
 }
 
 // NextRetrogradeToPrograde 上次留（逆转瞬）
-//// 返回上次逆转瞬留的时间
+// // 返回上次逆转瞬留的时间
 func NextRetrogradeToPrograde(date time.Time) time.Time {
 	jde := basic.TD2UT(basic.Date2JDE(date.UTC()), true)
 	return basic.JDE2DateByZone(basic.NextMarsRetrogradeToPrograde(jde), date.Location(), false)
diff --git a/mercury/mercury.go b/mercury/mercury.go
index f125401..a600c01 100644
--- a/mercury/mercury.go
+++ b/mercury/mercury.go
@@ -10,7 +10,9 @@ import (
 
 var (
 	ERR_MERCURY_NEVER_RISE = errors.New("ERROR:极夜，水星今日永远在地平线下！")
-	ERR_MERCURY_NEVER_DOWN = errors.New("ERROR:极昼，水星今日永远在地平线上！")
+	ERR_MERCURY_NEVER_SET  = errors.New("ERROR:极昼，水星今日永远在地平线上！")
+	// ERR_MERCURY_NEVER_DOWN deprecated -- use ERR_MERCURY_NEVER_SET instead
+	ERR_MERCURY_NEVER_DOWN = ERR_MERCURY_NEVER_SET
 )
 
 // ApparentLo 视黄经
@@ -122,11 +124,12 @@ func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_MERCURY_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_MERCURY_NEVER_DOWN
+		err = ERR_MERCURY_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
 
+// deprecated -- use SetTime instead
 // DownTime 落下时间
 // date，取日期，时区忽略
 // lon，经度，东正西负
@@ -134,6 +137,16 @@ func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 // height，高度
 // aero，true时进行大气修正
 func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
+	return SetTime(date, lon, lat, height, aero)
+}
+
+// SetTime 落下时间
+// date，取日期，时区忽略
+// lon，经度，东正西负
+// lat，纬度，北正南负
+// height，高度
+// aero，true时进行大气修正
+func SetTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
 	var err error
 	var aeroFloat float64
 	if aero {
@@ -150,7 +163,7 @@ func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_MERCURY_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_MERCURY_NEVER_DOWN
+		err = ERR_MERCURY_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
@@ -233,7 +246,7 @@ func LastRetrogradeToPrograde(date time.Time) time.Time {
 }
 
 // NextRetrogradeToPrograde 上次留（逆转瞬）
-//// 返回上次逆转瞬留的时间
+// // 返回上次逆转瞬留的时间
 func NextRetrogradeToPrograde(date time.Time) time.Time {
 	jde := basic.TD2UT(basic.Date2JDE(date.UTC()), true)
 	return basic.JDE2DateByZone(basic.NextMercuryRetrogradeToPrograde(jde), date.Location(), false)
diff --git a/mercury/mercury_test.go b/mercury/mercury_test.go
index be6a641..4762b9f 100644
--- a/mercury/mercury_test.go
+++ b/mercury/mercury_test.go
@@ -22,5 +22,5 @@ func TestMercury(t *testing.T) {
 	if date.Unix() != 1642636481 {
 		t.Fatal(date.Unix())
 	}
-	fmt.Println(DownTime(date, 115, 40, 0, false))
+	fmt.Println(SetTime(date, 115, 40, 0, false))
 }
diff --git a/moon/moon.go b/moon/moon.go
index b810112..a73766b 100644
--- a/moon/moon.go
+++ b/moon/moon.go
@@ -10,7 +10,9 @@ import (
 
 var (
 	ERR_MOON_NEVER_RISE = errors.New("ERROR:极夜，月亮在今日永远在地平线下！")
-	ERR_MOON_NEVER_DOWN = errors.New("ERROR:极昼，月亮在今日永远在地平线上！")
+	ERR_MOON_NEVER_SET  = errors.New("ERROR:极昼，月亮在今日永远在地平线上！")
+	// ERR_MOON_NEVER_DOWN deprecated -- use ERR_MOON_NEVER_SET instead
+	ERR_MOON_NEVER_DOWN = ERR_MOON_NEVER_SET
 	ERR_NOT_TODAY       = errors.New("ERROR:月亮已在（昨日/明日）（升起/降下）")
 )
 
@@ -164,19 +166,30 @@ func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_MOON_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_MOON_NEVER_DOWN
+		err = ERR_MOON_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
 
-// DownTime 月亮降下时间
+// deprecated -- use SetTime instead
+// DownTime 落下时间
+// date，取日期，时区忽略
+// lon，经度，东正西负
+// lat，纬度，北正南负
+// height，高度
+// aero，true时进行大气修正
+func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
+	return SetTime(date, lon, lat, height, aero)
+}
+
+// SetTime 月亮降下时间
 //
 //	date, 世界时（忽略此处时区）
 //	lon，经度，东正西负
 //	lat，纬度，北正南负
 //	height，高度
 //	aero，大气修正
-func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
+func SetTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
 	var err error
 	if date.Hour() > 12 {
 		date = date.Add(time.Hour * -12)
@@ -196,7 +209,7 @@ func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_MOON_NEVER_RISE
 	}
 	if downJde == -1 {
-		err = ERR_MOON_NEVER_DOWN
+		err = ERR_MOON_NEVER_SET
 	}
 	return basic.JDE2DateByZone(downJde, date.Location(), true), err
 }
diff --git a/neptune/neptune.go b/neptune/neptune.go
index 3acab57..d44a7a7 100644
--- a/neptune/neptune.go
+++ b/neptune/neptune.go
@@ -10,7 +10,9 @@ import (
 
 var (
 	ERR_NEPTUNE_NEVER_RISE = errors.New("ERROR:极夜，海王星今日永远在地平线下！")
-	ERR_NEPTUNE_NEVER_DOWN = errors.New("ERROR:极昼，海王星今日永远在地平线上！")
+	ERR_NEPTUNE_NEVER_SET  = errors.New("ERROR:极昼，海王星今日永远在地平线上！")
+	// ERR_NEPTUNE_NEVER_DOWN deprecated -- use ERR_NEPTUNE_NEVER_SET instead
+	ERR_NEPTUNE_NEVER_DOWN = ERR_NEPTUNE_NEVER_SET
 )
 
 // ApparentLo 视黄经
@@ -122,11 +124,12 @@ func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_NEPTUNE_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_NEPTUNE_NEVER_DOWN
+		err = ERR_NEPTUNE_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
 
+// deprecated -- use SetTime instead
 // DownTime 落下时间
 // date，取日期，时区忽略
 // lon，经度，东正西负
@@ -134,6 +137,16 @@ func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 // height，高度
 // aero，true时进行大气修正
 func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
+	return SetTime(date, lon, lat, height, aero)
+}
+
+// SetTime 落下时间
+// date，取日期，时区忽略
+// lon，经度，东正西负
+// lat，纬度，北正南负
+// height，高度
+// aero，true时进行大气修正
+func SetTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
 	var err error
 	var aeroFloat float64
 	if aero {
@@ -150,7 +163,7 @@ func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_NEPTUNE_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_NEPTUNE_NEVER_DOWN
+		err = ERR_NEPTUNE_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
@@ -205,7 +218,7 @@ func LastRetrogradeToPrograde(date time.Time) time.Time {
 }
 
 // NextRetrogradeToPrograde 上次留（逆转瞬）
-//// 返回上次逆转瞬留的时间
+// // 返回上次逆转瞬留的时间
 func NextRetrogradeToPrograde(date time.Time) time.Time {
 	jde := basic.TD2UT(basic.Date2JDE(date.UTC()), true)
 	return basic.JDE2DateByZone(basic.NextNeptuneRetrogradeToPrograde(jde), date.Location(), false)
diff --git a/neptune/neptune_test.go b/neptune/neptune_test.go
index 506b33c..09ec1c9 100644
--- a/neptune/neptune_test.go
+++ b/neptune/neptune_test.go
@@ -22,5 +22,5 @@ func TestNeptune(t *testing.T) {
 	if date.Unix() != 1642644398 {
 		t.Fatal(date.Unix())
 	}
-	fmt.Println(DownTime(date, 115, 40, 0, false))
+	fmt.Println(SetTime(date, 115, 40, 0, false))
 }
diff --git a/saturn/saturn.go b/saturn/saturn.go
index 7f94e7a..c8c577f 100644
--- a/saturn/saturn.go
+++ b/saturn/saturn.go
@@ -10,7 +10,9 @@ import (
 
 var (
 	ERR_SATURN_NEVER_RISE = errors.New("ERROR:极夜，木星今日永远在地平线下！")
-	ERR_SATURN_NEVER_DOWN = errors.New("ERROR:极昼，木星今日永远在地平线上！")
+	ERR_SATURN_NEVER_SET  = errors.New("ERROR:极昼，木星今日永远在地平线上！")
+	// ERR_SATURN_NEVER_DOWN deprecated -- use ERR_SATURN_NEVER_SET instead
+	ERR_SATURN_NEVER_DOWN = ERR_SATURN_NEVER_SET
 )
 
 // ApparentLo 视黄经
@@ -122,11 +124,12 @@ func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_SATURN_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_SATURN_NEVER_DOWN
+		err = ERR_SATURN_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
 
+// deprecated -- use SetTime instead
 // DownTime 落下时间
 // date，取日期，时区忽略
 // lon，经度，东正西负
@@ -134,6 +137,16 @@ func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 // height，高度
 // aero，true时进行大气修正
 func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
+	return SetTime(date, lon, lat, height, aero)
+}
+
+// SetTime 落下时间
+// date，取日期，时区忽略
+// lon，经度，东正西负
+// lat，纬度，北正南负
+// height，高度
+// aero，true时进行大气修正
+func SetTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
 	var err error
 	var aeroFloat float64
 	if aero {
@@ -150,7 +163,7 @@ func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_SATURN_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_SATURN_NEVER_DOWN
+		err = ERR_SATURN_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
@@ -205,7 +218,7 @@ func LastRetrogradeToPrograde(date time.Time) time.Time {
 }
 
 // NextRetrogradeToPrograde 上次留（逆转瞬）
-//// 返回上次逆转瞬留的时间
+// // 返回上次逆转瞬留的时间
 func NextRetrogradeToPrograde(date time.Time) time.Time {
 	jde := basic.TD2UT(basic.Date2JDE(date.UTC()), true)
 	return basic.JDE2DateByZone(basic.NextSaturnRetrogradeToPrograde(jde), date.Location(), false)
diff --git a/star/star.go b/star/star.go
index fe03aba..8a4f412 100644
--- a/star/star.go
+++ b/star/star.go
@@ -10,7 +10,9 @@ import (
 
 var (
 	ERR_STAR_NEVER_RISE = errors.New("ERROR:极夜，星星在今日永远在地平线下！")
-	ERR_STAR_NEVER_DOWN = errors.New("ERROR:极昼，星星在今日永远在地平线上！")
+	ERR_STAR_NEVER_SET  = errors.New("ERROR:极昼，星星在今日永远在地平线上！")
+	// ERR_STAR_NEVER_DOWN deprecated -- use ERR_STAR_NEVER_SET instead
+	ERR_STAR_NEVER_DOWN = ERR_STAR_NEVER_SET
 )
 
 // Constellation
@@ -52,11 +54,12 @@ func RiseTime(date time.Time, ra, dec, lon, lat, height float64, aero bool) (tim
 		err = ERR_STAR_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_STAR_NEVER_DOWN
+		err = ERR_STAR_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
 
+// deprecated -- use SetTime instead
 // DownTime 星星降落时间
 //
 //	date, 世界时（忽略此处时区）
@@ -67,6 +70,19 @@ func RiseTime(date time.Time, ra, dec, lon, lat, height float64, aero bool) (tim
 //	height，高度
 //	aero,是否进行大气修正
 func DownTime(date time.Time, ra, dec, lon, lat, height float64, aero bool) (time.Time, error) {
+	return SetTime(date, ra, dec, lon, lat, height, aero)
+}
+
+// SetTime 星星降落时间
+//
+//	date, 世界时（忽略此处时区）
+//	ra，Date瞬时赤经
+//	dec，Date瞬时赤纬
+//	lon，经度，东正西负
+//	lat，纬度，北正南负
+//	height，高度
+//	aero,是否进行大气修正
+func SetTime(date time.Time, ra, dec, lon, lat, height float64, aero bool) (time.Time, error) {
 	var err error
 	if date.Hour() > 12 {
 		date = date.Add(time.Hour * -12)
@@ -79,7 +95,7 @@ func DownTime(date time.Time, ra, dec, lon, lat, height float64, aero bool) (tim
 		err = ERR_STAR_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_STAR_NEVER_DOWN
+		err = ERR_STAR_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
diff --git a/star/star_test.go b/star/star_test.go
index a7bf242..c0d6c76 100644
--- a/star/star_test.go
+++ b/star/star_test.go
@@ -22,5 +22,5 @@ func TestStar(t *testing.T) {
 	fmt.Println(tools.Format(ra/15, 1), tools.Format(dec, 0))
 	fmt.Println(RiseTime(now, ra, dec, 115, 40, 0, true))
 	fmt.Println(CulminationTime(now, ra, 115))
-	fmt.Println(DownTime(now, ra, dec, 115, 40, 0, true))
+	fmt.Println(SetTime(now, ra, dec, 115, 40, 0, true))
 }
diff --git a/sun/sun.go b/sun/sun.go
index d3f95dd..8b242be 100644
--- a/sun/sun.go
+++ b/sun/sun.go
@@ -8,8 +8,10 @@ import (
 )
 
 var (
-	ERR_SUN_NEVER_RISE      = errors.New("ERROR:极夜，太阳在今日永远在地平线下！")
-	ERR_SUN_NEVER_DOWN      = errors.New("ERROR:极昼，太阳在今日永远在地平线上！")
+	ERR_SUN_NEVER_RISE = errors.New("ERROR:极夜，太阳在今日永远在地平线下！")
+	ERR_SUN_NEVER_SET  = errors.New("ERROR:极昼，太阳在今日永远在地平线上！")
+	// ERR_SUN_NEVER_DOWN deprecated -- use ERR_SUN_NEVER_RISE instead
+	ERR_SUN_NEVER_DOWN      = ERR_SUN_NEVER_SET
 	ERR_TWILIGHT_NOT_EXISTS = errors.New("ERROR:今日晨昏朦影不存在！")
 )
 
@@ -47,18 +49,29 @@ func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_SUN_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_SUN_NEVER_DOWN
+		err = ERR_SUN_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
 
-// SunDownTime 太阳落下时间
+// deprecated -- use SetTime instead
+// DownTime 太阳落下时间
 // date，当地时区日期，务必做时区修正
 // lon，经度，东正西负
 // lat，纬度，北正南负
 // height，高度
 // aero，true时进行大气修正
 func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
+	return SetTime(date, lon, lat, height, aero)
+}
+
+// SetTime 太阳落下时间
+// date，当地时区日期，务必做时区修正
+// lon，经度，东正西负
+// lat，纬度，北正南负
+// height，高度
+// aero，true时进行大气修正
+func SetTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, error) {
 	var err error
 	var aeroFloat float64
 	if aero {
@@ -70,12 +83,12 @@ func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 	jde := basic.Date2JDE(date)
 	_, loc := date.Zone()
 	timezone := float64(loc) / 3600.0
-	downJde := basic.GetSunDownTime(jde, lon, lat, timezone, aeroFloat, height)
+	downJde := basic.GetSunSetTime(jde, lon, lat, timezone, aeroFloat, height)
 	if downJde == -2 {
 		err = ERR_SUN_NEVER_RISE
 	}
 	if downJde == -1 {
-		err = ERR_SUN_NEVER_DOWN
+		err = ERR_SUN_NEVER_SET
 	}
 	return basic.JDE2DateByZone(downJde, date.Location(), true), err
 }
@@ -177,7 +190,7 @@ func TrueLo(date time.Time) float64 {
 func TrueBo(date time.Time) float64 {
 	//转换为UTC时间
 	jde := basic.Date2JDE(date.UTC())
-	return basic.HSunTrueLo(basic.TD2UT(jde, true))
+	return basic.HSunTrueBo(basic.TD2UT(jde, true))
 }
 
 // ApparentLo 太阳视黄经
diff --git a/sun/sun_test.go b/sun/sun_test.go
index 196e232..6616bf9 100644
--- a/sun/sun_test.go
+++ b/sun/sun_test.go
@@ -2,6 +2,7 @@ package sun
 
 import (
 	"fmt"
+	"math"
 	"testing"
 	"time"
 )
@@ -22,8 +23,12 @@ func TestSun(t *testing.T) {
 	if d.Format("2006-01-02 15:04:05") != "2020-01-01 08:41:45" {
 		t.Fatal(d.Format("2006-01-02 15:04:05"))
 	}
+	bo := TrueBo(now)
+	if math.Abs(bo) > 2 {
+		t.Fatal(bo)
+	}
 	fmt.Println(CulminationTime(now, 115))
-	fmt.Println(DownTime(now, 115, 40, 0, true))
+	fmt.Println(SetTime(now, 115, 40, 0, true))
 	fmt.Println(MorningTwilight(now, 115, 40, -6))
 	fmt.Println(EveningTwilight(now, 115, 40, -6))
 }
diff --git a/uranus/uranus.go b/uranus/uranus.go
index c9aaf91..b1353c9 100644
--- a/uranus/uranus.go
+++ b/uranus/uranus.go
@@ -10,7 +10,9 @@ import (
 
 var (
 	ERR_URANUS_NEVER_RISE = errors.New("ERROR:极夜，天王星今日永远在地平线下！")
-	ERR_URANUS_NEVER_DOWN = errors.New("ERROR:极昼，天王星今日永远在地平线上！")
+	ERR_URANUS_NEVER_SET  = errors.New("ERROR:极昼，天王星今日永远在地平线上！")
+	// ERR_URANUS_NEVER_DOWN deprecated -- use ERR_URANUS_NEVER_SET instead
+	ERR_URANUS_NEVER_DOWN = ERR_URANUS_NEVER_SET
 )
 
 // ApparentLo 视黄经
@@ -122,7 +124,7 @@ func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_URANUS_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_URANUS_NEVER_DOWN
+		err = ERR_URANUS_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
@@ -150,7 +152,7 @@ func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_URANUS_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_URANUS_NEVER_DOWN
+		err = ERR_URANUS_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
@@ -205,7 +207,7 @@ func LastRetrogradeToPrograde(date time.Time) time.Time {
 }
 
 // NextRetrogradeToPrograde 上次留（逆转瞬）
-//// 返回上次逆转瞬留的时间
+// // 返回上次逆转瞬留的时间
 func NextRetrogradeToPrograde(date time.Time) time.Time {
 	jde := basic.TD2UT(basic.Date2JDE(date.UTC()), true)
 	return basic.JDE2DateByZone(basic.NextUranusRetrogradeToPrograde(jde), date.Location(), false)
diff --git a/venus/venus.go b/venus/venus.go
index ddadd4d..dc1f4c0 100644
--- a/venus/venus.go
+++ b/venus/venus.go
@@ -10,7 +10,9 @@ import (
 
 var (
 	ERR_VENUS_NEVER_RISE = errors.New("ERROR:极夜，金星今日永远在地平线下！")
-	ERR_VENUS_NEVER_DOWN = errors.New("ERROR:极昼，金星今日永远在地平线上！")
+	ERR_VENUS_NEVER_SET  = errors.New("ERROR:极昼，金星今日永远在地平线上！")
+	// ERR_VENUS_NEVER_DOWN deprecated -- use ERR_VENUS_NEVER_SET instead
+	ERR_VENUS_NEVER_DOWN = ERR_VENUS_NEVER_SET
 )
 
 // ApparentLo 视黄经
@@ -122,7 +124,7 @@ func RiseTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_VENUS_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_VENUS_NEVER_DOWN
+		err = ERR_VENUS_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
@@ -150,7 +152,7 @@ func DownTime(date time.Time, lon, lat, height float64, aero bool) (time.Time, e
 		err = ERR_VENUS_NEVER_RISE
 	}
 	if riseJde == -1 {
-		err = ERR_VENUS_NEVER_DOWN
+		err = ERR_VENUS_NEVER_SET
 	}
 	return basic.JDE2DateByZone(riseJde, date.Location(), true), err
 }
@@ -233,7 +235,7 @@ func LastRetrogradeToPrograde(date time.Time) time.Time {
 }
 
 // NextRetrogradeToPrograde 上次留（逆转瞬）
-//// 返回上次逆转瞬留的时间
+// // 返回上次逆转瞬留的时间
 func NextRetrogradeToPrograde(date time.Time) time.Time {
 	jde := basic.TD2UT(basic.Date2JDE(date.UTC()), true)
 	return basic.JDE2DateByZone(basic.NextVenusRetrogradeToPrograde(jde), date.Location(), false)