diff --git a/carbon.go b/carbon.go
index e96d29f..0ae90b0 100644
--- a/carbon.go
+++ b/carbon.go
@@ -127,28 +127,31 @@ const (
 // layout constants
 // 布局模板常量
 const (
-	ANSICLayout              = time.ANSIC
-	UnixDateLayout           = time.UnixDate
-	RubyDateLayout           = time.RubyDate
-	RFC822Layout             = time.RFC822
-	RFC822ZLayout            = time.RFC822Z
-	RFC850Layout             = time.RFC850
-	RFC1123Layout            = time.RFC1123
-	RFC1123ZLayout           = time.RFC1123Z
-	RssLayout                = time.RFC1123Z
-	KitchenLayout            = time.Kitchen
-	RFC2822Layout            = time.RFC1123Z
-	CookieLayout             = "Monday, 02-Jan-2006 15:04:05 MST"
-	RFC3339Layout            = "2006-01-02T15:04:05Z07:00"
-	RFC3339MilliLayout       = "2006-01-02T15:04:05.999Z07:00"
-	RFC3339MicroLayout       = "2006-01-02T15:04:05.999999Z07:00"
-	RFC3339NanoLayout        = "2006-01-02T15:04:05.999999999Z07:00"
-	ISO8601Layout            = "2006-01-02T15:04:05-07:00"
-	ISO8601MilliLayout       = "2006-01-02T15:04:05.999-07:00"
-	ISO8601MicroLayout       = "2006-01-02T15:04:05.999999-07:00"
-	ISO8601NanoLayout        = "2006-01-02T15:04:05.999999999-07:00"
-	RFC1036Layout            = "Mon, 02 Jan 06 15:04:05 -0700"
-	RFC7231Layout            = "Mon, 02 Jan 2006 15:04:05 MST"
+	ANSICLayout    = time.ANSIC
+	CookieLayout   = "Monday, 02-Jan-2006 15:04:05 MST"
+	KitchenLayout  = time.Kitchen
+	RssLayout      = time.RFC1123Z
+	RubyDateLayout = time.RubyDate
+	UnixDateLayout = time.UnixDate
+
+	RFC1036Layout      = "Mon, 02 Jan 06 15:04:05 -0700"
+	RFC1123Layout      = time.RFC1123
+	RFC1123ZLayout     = time.RFC1123Z
+	RFC2822Layout      = time.RFC1123Z
+	RFC3339Layout      = "2006-01-02T15:04:05Z07:00"
+	RFC3339MilliLayout = "2006-01-02T15:04:05.999Z07:00"
+	RFC3339MicroLayout = "2006-01-02T15:04:05.999999Z07:00"
+	RFC3339NanoLayout  = "2006-01-02T15:04:05.999999999Z07:00"
+	RFC7231Layout      = "Mon, 02 Jan 2006 15:04:05 MST"
+	RFC822Layout       = time.RFC822
+	RFC822ZLayout      = time.RFC822Z
+	RFC850Layout       = time.RFC850
+
+	ISO8601Layout      = "2006-01-02T15:04:05-07:00"
+	ISO8601MilliLayout = "2006-01-02T15:04:05.999-07:00"
+	ISO8601MicroLayout = "2006-01-02T15:04:05.999999-07:00"
+	ISO8601NanoLayout  = "2006-01-02T15:04:05.999999999-07:00"
+
 	DayDateTimeLayout        = "Mon, Jan 2, 2006 3:04 PM"
 	DateTimeLayout           = "2006-01-02 15:04:05"
 	DateTimeMilliLayout      = "2006-01-02 15:04:05.999"
@@ -158,22 +161,24 @@ const (
 	ShortDateTimeMilliLayout = "20060102150405.999"
 	ShortDateTimeMicroLayout = "20060102150405.999999"
 	ShortDateTimeNanoLayout  = "20060102150405.999999999"
-	DateLayout               = "2006-01-02"
-	DateMilliLayout          = "2006-01-02.999"
-	DateMicroLayout          = "2006-01-02.999999"
-	DateNanoLayout           = "2006-01-02.999999999"
-	ShortDateLayout          = "20060102"
-	ShortDateMilliLayout     = "20060102.999"
-	ShortDateMicroLayout     = "20060102.999999"
-	ShortDateNanoLayout      = "20060102.999999999"
-	TimeLayout               = "15:04:05"
-	TimeMilliLayout          = "15:04:05.999"
-	TimeMicroLayout          = "15:04:05.999999"
-	TimeNanoLayout           = "15:04:05.999999999"
-	ShortTimeLayout          = "150405"
-	ShortTimeMilliLayout     = "150405.999"
-	ShortTimeMicroLayout     = "150405.999999"
-	ShortTimeNanoLayout      = "150405.999999999"
+
+	DateLayout           = "2006-01-02"
+	DateMilliLayout      = "2006-01-02.999"
+	DateMicroLayout      = "2006-01-02.999999"
+	DateNanoLayout       = "2006-01-02.999999999"
+	ShortDateLayout      = "20060102"
+	ShortDateMilliLayout = "20060102.999"
+	ShortDateMicroLayout = "20060102.999999"
+	ShortDateNanoLayout  = "20060102.999999999"
+
+	TimeLayout           = "15:04:05"
+	TimeMilliLayout      = "15:04:05.999"
+	TimeMicroLayout      = "15:04:05.999999"
+	TimeNanoLayout       = "15:04:05.999999999"
+	ShortTimeLayout      = "150405"
+	ShortTimeMilliLayout = "150405.999"
+	ShortTimeMicroLayout = "150405.999999"
+	ShortTimeNanoLayout  = "150405.999999999"
 )
 
 // Carbon defines a Carbon struct.
diff --git a/json_test.go b/json_test.go
index be88920..a06afae 100644
--- a/json_test.go
+++ b/json_test.go
@@ -12,58 +12,29 @@ type Person struct {
 	Name string `json:"name"`
 	Age  int    `json:"age"`
 
-	Birthday1 Carbon `json:"birthday1" carbon:"layout:2006-01-02 15:04:05"`
-	Birthday2 Carbon `json:"birthday2" carbon:"layout:2006-01-02 15:04:05.999"`
-	Birthday3 Carbon `json:"birthday3" carbon:"layout:2006-01-02 15:04:05.999999"`
-	Birthday4 Carbon `json:"birthday4" carbon:"layout:2006-01-02 15:04:05.999999999"`
+	Birthday0 Carbon `json:"birthday0"`
 
-	GraduatedAt1 Carbon `json:"graduated_at1" carbon:"layout:2006-01-02"`
-	GraduatedAt2 Carbon `json:"graduated_at2" carbon:"layout:2006-01-02.999"`
-	GraduatedAt3 Carbon `json:"graduated_at3" carbon:"layout:2006-01-02.999999"`
-	GraduatedAt4 Carbon `json:"graduated_at4" carbon:"layout:2006-01-02.999999999"`
+	Birthday1 Carbon `json:"birthday1" carbon:"layout:2006-01-02"`
+	Birthday2 Carbon `json:"birthday2" carbon:"layout:15:04:05"`
+	Birthday3 Carbon `json:"birthday3" carbon:"layout:2006-01-02 15:04:05"`
 
-	OperatedAt1 Carbon `json:"operated_at1" carbon:"layout:15:04:05"`
-	OperatedAt2 Carbon `json:"operated_at2" carbon:"layout:15:04:05.999"`
-	OperatedAt3 Carbon `json:"operated_at3" carbon:"layout:15:04:05.999999"`
-	OperatedAt4 Carbon `json:"operated_at4" carbon:"layout:15:04:05.999999999"`
-
-	CreatedAt1 Carbon `json:"created_at1" carbon:"format:Y-m-d"`
-	CreatedAt2 Carbon `json:"created_at2" carbon:"format:H:i:s"`
-	CreatedAt3 Carbon `json:"created_at3" carbon:"format:Y-m-d H:i:s"`
-	CreatedAt4 Carbon `json:"created_at4"`
-}
-
-type Student struct {
-	Name     string `json:"name"`
-	Age      int    `json:"age"`
-	Birthday Carbon `json:"birthday"`
+	Birthday4 Carbon `json:"birthday4" carbon:"format:Y-m-d"`
+	Birthday5 Carbon `json:"birthday5" carbon:"format:H:i:s"`
+	Birthday6 Carbon `json:"birthday6" carbon:"format:Y-m-d H:i:s"`
 }
 
 func TestCarbon_MarshalJSON_LoadTag(t *testing.T) {
 	c := Parse("2020-08-05 13:14:15.999999999", PRC)
 	person := Person{
-		Name: "gouguoyin",
-		Age:  18,
-
+		Name:      "gouguoyin",
+		Age:       18,
+		Birthday0: c,
 		Birthday1: c,
 		Birthday2: c,
 		Birthday3: c,
 		Birthday4: c,
-
-		GraduatedAt1: c,
-		GraduatedAt2: c,
-		GraduatedAt3: c,
-		GraduatedAt4: c,
-
-		OperatedAt1: c,
-		OperatedAt2: c,
-		OperatedAt3: c,
-		OperatedAt4: c,
-
-		CreatedAt1: c,
-		CreatedAt2: c,
-		CreatedAt3: c,
-		CreatedAt4: c,
+		Birthday5: c,
+		Birthday6: c,
 	}
 
 	loadErr := LoadTag(&person)
@@ -72,64 +43,55 @@ func TestCarbon_MarshalJSON_LoadTag(t *testing.T) {
 	data, marshalErr := json.Marshal(&person)
 	assert.Nil(t, marshalErr)
 
-	assert.Equal(t, "2020-08-05 13:14:15", person.Birthday1.String())
-	assert.Equal(t, "2020-08-05 13:14:15.999", person.Birthday2.String())
-	assert.Equal(t, "2020-08-05 13:14:15.999999", person.Birthday3.String())
-	assert.Equal(t, "2020-08-05 13:14:15.999999999", person.Birthday4.String())
+	assert.Equal(t, "2020-08-05 13:14:15", person.Birthday0.String())
 
-	assert.Equal(t, "2020-08-05", person.GraduatedAt1.String())
-	assert.Equal(t, "2020-08-05.999", person.GraduatedAt2.String())
-	assert.Equal(t, "2020-08-05.999999", person.GraduatedAt3.String())
-	assert.Equal(t, "2020-08-05.999999999", person.GraduatedAt4.String())
+	assert.Equal(t, "2020-08-05", person.Birthday1.String())
+	assert.Equal(t, "13:14:15", person.Birthday2.String())
+	assert.Equal(t, "2020-08-05 13:14:15", person.Birthday3.String())
 
-	assert.Equal(t, "13:14:15", person.OperatedAt1.String())
-	assert.Equal(t, "13:14:15.999", person.OperatedAt2.String())
-	assert.Equal(t, "13:14:15.999999", person.OperatedAt3.String())
-	assert.Equal(t, "13:14:15.999999999", person.OperatedAt4.String())
-
-	assert.Equal(t, "2020-08-05", person.CreatedAt1.String())
-	assert.Equal(t, "13:14:15", person.CreatedAt2.String())
-	assert.Equal(t, "2020-08-05 13:14:15", person.CreatedAt3.String())
-	assert.Equal(t, "2020-08-05 13:14:15", person.CreatedAt4.String())
+	assert.Equal(t, "2020-08-05", person.Birthday4.String())
+	assert.Equal(t, "13:14:15", person.Birthday5.String())
+	assert.Equal(t, "2020-08-05 13:14:15", person.Birthday6.String())
 
 	fmt.Printf("person output by json:\n%s\n", data)
 }
 
 func TestCarbon_MarshalJSON_UnLoadTag(t *testing.T) {
 	c := Parse("2020-08-05 13:14:15.999999999", PRC)
-	student := Student{
-		Name:     "gouguoyin",
-		Age:      18,
-		Birthday: c,
+	person := Person{
+		Name:      "gouguoyin",
+		Age:       18,
+		Birthday1: c,
+		Birthday2: c,
+		Birthday3: c,
+		Birthday4: c,
+		Birthday5: c,
+		Birthday6: c,
 	}
 
-	data, marshalErr := json.Marshal(&student)
+	data, marshalErr := json.Marshal(&person)
 	assert.Nil(t, marshalErr)
 
-	assert.Equal(t, "2020-08-05 13:14:15", student.Birthday.String())
+	assert.Equal(t, "2020-08-05 13:14:15", person.Birthday1.String())
+	assert.Equal(t, "2020-08-05 13:14:15", person.Birthday2.String())
+	assert.Equal(t, "2020-08-05 13:14:15", person.Birthday3.String())
+	assert.Equal(t, "2020-08-05 13:14:15", person.Birthday4.String())
+	assert.Equal(t, "2020-08-05 13:14:15", person.Birthday5.String())
+	assert.Equal(t, "2020-08-05 13:14:15", person.Birthday6.String())
 	fmt.Printf("student output by json:\n%s\n", data)
 }
 
 func TestCarbon_UnmarshalJSON_LoadTag(t *testing.T) {
 	str := `{
-		"name": "gouguoyin",
-		"age": 18,
-		"birthday1": "2020-08-05 13:14:15",
-		"birthday2": "2020-08-05 13:14:15.999",
-		"birthday3": "2020-08-05 13:14:15.999999",
-		"birthday4": "2020-08-05 13:14:15.999999999",
-		"graduated_at1": "2020-08-05",
-		"graduated_at2": "2020-08-05.999",
-		"graduated_at3": "2020-08-05.999999",
-		"graduated_at4": "2020-08-05.999999999",
-		"operated_at1": "13:14:15",
-		"operated_at2": "13:14:15.999",
-		"operated_at3": "13:14:15.999999",
-		"operated_at4": "13:14:15.999999999",
-		"created_at1": "2020-08-05",
-		"created_at2": "13:14:15",
-		"created_at3": "2020-08-05 13:14:15",
-		"created_at4": "2020-08-05 13:14:15"
+		"name":"gouguoyin",
+		"age":18,
+		"birthday0":"2020-08-05 13:14:15",
+		"birthday1":"2020-08-05",
+		"birthday2":"13:14:15",
+		"birthday3":"2020-08-05 13:14:15",
+		"birthday4":"2020-08-05",
+		"birthday5":"13:14:15",
+		"birthday6":"2020-08-05 13:14:15"
 	}`
 
 	var person Person
@@ -140,60 +102,51 @@ func TestCarbon_UnmarshalJSON_LoadTag(t *testing.T) {
 	unmarshalErr := json.Unmarshal([]byte(str), &person)
 	assert.Nil(t, unmarshalErr)
 
-	assert.Equal(t, "2020-08-05 13:14:15", person.Birthday1.String())
-	assert.Equal(t, "2020-08-05 13:14:15.999", person.Birthday2.String())
-	assert.Equal(t, "2020-08-05 13:14:15.999999", person.Birthday3.String())
-	assert.Equal(t, "2020-08-05 13:14:15.999999999", person.Birthday4.String())
-
-	assert.Equal(t, "2020-08-05", person.GraduatedAt1.String())
-	assert.Equal(t, "2020-08-05.999", person.GraduatedAt2.String())
-	assert.Equal(t, "2020-08-05.999999", person.GraduatedAt3.String())
-	assert.Equal(t, "2020-08-05.999999999", person.GraduatedAt4.String())
-
-	assert.Equal(t, "13:14:15", person.OperatedAt1.String())
-	assert.Equal(t, "13:14:15.999", person.OperatedAt2.String())
-	assert.Equal(t, "13:14:15.999999", person.OperatedAt3.String())
-	assert.Equal(t, "13:14:15.999999999", person.OperatedAt4.String())
-
-	assert.Equal(t, "2020-08-05", person.CreatedAt1.String())
-	assert.Equal(t, "13:14:15", person.CreatedAt2.String())
-	assert.Equal(t, "2020-08-05 13:14:15", person.CreatedAt3.String())
+	assert.Equal(t, "2020-08-05 13:14:15", person.Birthday0.String())
+	assert.Equal(t, "2020-08-05", person.Birthday1.String())
+	assert.Equal(t, "13:14:15", person.Birthday2.String())
+	assert.Equal(t, "2020-08-05 13:14:15", person.Birthday3.String())
+	assert.Equal(t, "2020-08-05", person.Birthday4.String())
+	assert.Equal(t, "13:14:15", person.Birthday5.String())
+	assert.Equal(t, "2020-08-05 13:14:15", person.Birthday6.String())
 
 	fmt.Printf("Json string parse to person:\n%+v\n", person)
 }
 
 func TestCarbon_UnmarshalJSON_UnLoadTag(t *testing.T) {
 	str := `{
-		"name": "gouguoyin",
-		"age": 18,
-		"birthday": "2020-08-05 13:14:15.999"
+		"name":"gouguoyin",
+		"age":18,
+		"birthday0":"2020-08-05 13:14:15",
+		"birthday1":"2020-08-05"
 	}`
 
-	var student Student
-	unmarshalErr := json.Unmarshal([]byte(str), &student)
+	var person Person
+	unmarshalErr := json.Unmarshal([]byte(str), &person)
 	assert.Nil(t, unmarshalErr)
 
-	assert.Equal(t, "2020-08-05 13:14:15", student.Birthday.String())
-	fmt.Printf("Json string parse to student:\n%+v\n", student)
+	assert.Equal(t, "2020-08-05 13:14:15", person.Birthday0.String())
+	assert.Equal(t, "2020-08-05 00:00:00", person.Birthday1.String())
+	fmt.Printf("Json string parse to person:\n%+v\n", person)
 }
 
 func TestError_JSON(t *testing.T) {
-	student := Student{
-		Name:     "gouguoyin",
-		Age:      18,
-		Birthday: Parse("XXX"),
+	person := Person{
+		Name:      "gouguoyin",
+		Age:       18,
+		Birthday1: Parse("XXX"),
 	}
 
-	_, marshalErr := json.Marshal(student)
-	fmt.Println("marshal error", marshalErr.Error())
+	_, marshalErr := json.Marshal(person)
+	fmt.Println("marshal error:", marshalErr.Error())
 	assert.NotNil(t, marshalErr)
 
 	str := `{
 		"name": "gouguoyin",
 		"age": 18,
-		"birthday": "2020-08-05 13:14:15.999"
+		"birthday1": "2020-08-05 13:14:15"
 	}`
-	unmarshalErr := json.Unmarshal([]byte(str), &student)
-	fmt.Println("unmarshal error", unmarshalErr.Error())
+	unmarshalErr := json.Unmarshal([]byte(str), &person)
+	fmt.Println("unmarshal error:", unmarshalErr.Error())
 	assert.NotNil(t, unmarshalErr)
 }
diff --git a/tag.go b/tag.go
index 5276ca1..f953e36 100644
--- a/tag.go
+++ b/tag.go
@@ -61,6 +61,7 @@ func LoadTag(v interface{}) error {
 			continue
 		}
 		tag := field.Tag.Get("carbon")
+
 		if tag == "" {
 			tag = "layout:" + DateTimeLayout
 		}