diff --git a/date/carbon/carbon.go b/date/carbon/carbon.go
index f7bb5c8..fc4341f 100644
--- a/date/carbon/carbon.go
+++ b/date/carbon/carbon.go
@@ -1,9 +1,12 @@
 package carbon
 
 import (
+	"fmt"
+	"strconv"
 	"time"
 
 	"github.com/Kretech/xgo/date"
+	"github.com/pkg/errors"
 )
 
 // Carbon
@@ -12,19 +15,32 @@ type Carbon struct {
 }
 
 // 假定多数情况下，一个进程给一个location就够了
-var defaultLoc = time.Local
+var currentLoc = time.Local
 
 // 设置全局时区
 func In(loc *time.Location) {
-	defaultLoc = loc
+	currentLoc = loc
+	time.Local = loc
 }
 
 func Now() *Carbon {
 	return &Carbon{time.Now()}
 }
 
+func Today() *Carbon {
+	return &Carbon{time.Time{}.Truncate(24 * Hour)}
+}
+
+func Yestoday() *Carbon {
+	return Today().Sub(Day)
+}
+
+func Tomorrow() *Carbon {
+	return Today().Add(Day)
+}
+
 func UnixOf(sec int64, nsec int64) *Carbon {
-	t := time.Unix(sec, nsec).In(defaultLoc)
+	t := time.Unix(sec, nsec)
 	return &Carbon{t}
 }
 
@@ -33,21 +49,29 @@ func TimeOf(t time.Time) *Carbon {
 }
 
 // 解析时间文本
-func StrOf(str string) *Carbon {
-	return Parse(str)
+func strOf(str string) *Carbon {
+	return parse(str)
 }
 
 // todo
 // alias to StrOf
-func Parse(str string) *Carbon {
-	t := time.Now().In(defaultLoc)
+func parse(str string) *Carbon {
+	t := time.Now().In(currentLoc)
 	return &Carbon{t}
 }
 
 // wrap of time.Parse but with the carbon layout
 // 使用 Go time.Time 解析时间文本
-func TParse(layout, value string) *Carbon {
-	t, _ := time.Parse(date.ToGoFormat(layout), value)
+func ParseUTC(layout, value string) *Carbon {
+	return ParseIn(layout, value, UTC)
+}
+
+func ParseLocal(layout, value string) *Carbon {
+	return ParseIn(layout, value, time.Local)
+}
+
+func ParseIn(layout, value string, loc *time.Location) *Carbon {
+	t, _ := time.ParseInLocation(date.ToGoFormat(layout), value, loc)
 	return TimeOf(t)
 }
 
@@ -75,7 +99,7 @@ func (c Carbon) Add(d time.Duration) *Carbon {
 }
 
 // 减去另一个时间：计算两个时间的差
-func (c *Carbon) SubTime(t time.Time) time.Duration {
+func (c *Carbon) Diff(t time.Time) time.Duration {
 	return c.Time().Sub(t)
 }
 
@@ -88,7 +112,47 @@ func (c Carbon) Sub(d time.Duration) *Carbon {
 // Format 格式化代码
 // c.Format("Y-m-d H:i:s")
 // @see http://php.net/manual/zh/function.date.php#refsect1-function.date-parameters
-func (c *Carbon) Format(format string) string {
-	format = date.ToGoFormat(format)
-	return c.t.Format(format)
+func (c *Carbon) Format(layout string) string {
+	layout = date.ToGoFormat(layout)
+	return c.t.Format(layout)
+}
+
+func (this *Carbon) Unix() int64 {
+	return this.t.Unix()
+}
+
+func (this *Carbon) UnixNano() int64 {
+	return this.t.UnixNano()
+}
+
+func (this *Carbon) Truncate(d time.Duration) *Carbon {
+	return TimeOf(this.t.Truncate(d))
+}
+
+func (c *Carbon) String() string {
+	return c.DatetimeString()
+}
+
+func (c *Carbon) DateString() string {
+	return c.Format("Y-m-d")
+}
+
+func (c *Carbon) DatetimeString() string {
+	return c.Format("Y-m-d H:i:s")
+}
+
+func (c *Carbon) UnmarshalJSON(b []byte) (err error) {
+	unix, err := strconv.Atoi(string(b))
+	if err != nil {
+		err = errors.WithMessage(err, `Carbon UnmarshalJSON`)
+		return
+	}
+
+	*c = *UnixOf(int64(unix), 0)
+
+	return
+}
+
+func (c *Carbon) MarshalJSON() ([]byte, error) {
+	return []byte(fmt.Sprint(c.Unix())), nil
 }
diff --git a/date/carbon/carbon_test.go b/date/carbon/carbon_test.go
index 3e4f1c9..f377728 100644
--- a/date/carbon/carbon_test.go
+++ b/date/carbon/carbon_test.go
@@ -1,6 +1,9 @@
 package carbon
 
 import (
+	"encoding/json"
+	"fmt"
+	"strconv"
 	"testing"
 	"time"
 
@@ -25,8 +28,8 @@ func TestUnixOf(t *testing.T) {
 }
 
 func TestParse(t *testing.T) {
-	Parse("2012-1-1 01:02:03")
-	Parse("+1 day")
+	parse("2012-1-1 01:02:03")
+	parse("+1 day")
 }
 
 func TestCarbon_Format(t *testing.T) {
@@ -49,7 +52,55 @@ func TestCarbon_In(t *testing.T) {
 }
 
 func TestCarbon_Sub(t *testing.T) {
-	t1 := TParse("Y-m-d H:i:s", "2018-01-02 09:00:00")
+	t1 := ParseUTC("Y-m-d H:i:s", "2018-01-02 09:00:00")
 	t2 := t1.Sub(time.Hour)
 	test.AssertEqual(t, t2.Format("Y-m-d H:i:s"), "2018-01-02 08:00:00")
 }
+
+func TestCarbon_MarshalJSO2N(t *testing.T) {
+
+	t0 := ParseUTC("Y-m-d H:i:s", "1970-01-01 00:00:00")
+	js, err := json.Marshal(t0)
+	test.AssertNil(t, err)
+
+	test.AssertEqual(t, string(js), `0`)
+
+	t1 := ParseUTC("Y-m-d H:i:s", "2018-01-02 01:00:00")
+	js, err = json.Marshal(t1)
+	test.AssertNil(t, err)
+
+	test.AssertEqual(t, string(js), `1514854800`)
+}
+
+func TestCarbon_MarshalJSON(t *testing.T) {
+	type args struct {
+		*time.Location
+		str     string
+		unixStr string
+	}
+	tests := []struct {
+		name string
+		args args
+	}{
+		// TODO: Add test cases.
+		{``, args{UTC, `1970-01-01 00:00:00`, `0`}},
+		{``, args{Shanghai, `1970-01-01 08:00:00`, `0`}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			c := ParseIn(`Y-m-d H:i:s`, tt.args.str, tt.args.Location)
+			unixBytes, err := c.MarshalJSON()
+
+			test.AssertNil(t, err)
+			test.AssertEqual(t, string(unixBytes), tt.args.unixStr)
+
+			unix, _ := strconv.Atoi(tt.args.unixStr)
+			unix += 3600
+			unixStr := fmt.Sprint(unix)
+			var c2 Carbon
+			err = json.Unmarshal([]byte(unixStr), &c2)
+			test.AssertNil(t, err)
+			test.AssertEqual(t, c.Add(time.Hour).String(), c2.String())
+		})
+	}
+}
diff --git a/date/carbon/location.go b/date/carbon/location.go
index 8f50715..1661bac 100644
--- a/date/carbon/location.go
+++ b/date/carbon/location.go
@@ -3,5 +3,6 @@ package carbon
 import "time"
 
 var (
+	UTC         = time.UTC
 	Shanghai, _ = time.LoadLocation("Asia/Shanghai")
 )
diff --git a/date/carbon/readme.md b/date/carbon/readme.md
new file mode 100644
index 0000000..b40eb6d
--- /dev/null
+++ b/date/carbon/readme.md
@@ -0,0 +1,2 @@
+# Carbon
+
diff --git a/date/date.go b/date/date.go
index e81c4b0..d538449 100644
--- a/date/date.go
+++ b/date/date.go
@@ -12,6 +12,7 @@ func TimeOffset(offset time.Duration) {
 }
 
 // ToGoFormat 把 Y-m-d 转成 Go 格式
+// cache ?
 func ToGoFormat(format string) string {
 	rule := []string{
 		`Y`, `2006`, //  年
@@ -80,7 +81,7 @@ func LocalFormat(format string, timestamp ...int64) string {
 // @see http://php.net/manual/en/function.strtotime.php#example-2803
 func StrToTime(expr string) int64 {
 	t := time.Now().Local()
-	//pattern := `\d+ [(year)|(month)|(day)|(hour)|(minute)|(second)]`
+	//pattern := `(\d+|[(last)|(next)]) [(year)|(month)|(day)|(hour)|(minute)|(second)|(Monday)]`
 
 	for i := 1; i < 10; i++ {