diff --git a/boundary_bench_test.go b/boundary_bench_test.go
index ef4dde9..7978322 100755
--- a/boundary_bench_test.go
+++ b/boundary_bench_test.go
@@ -6,6 +6,9 @@ import (
 
 func BenchmarkCarbon_StartOfCentury(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().StartOfCentury()
+	}
 	for n := 0; n < b.N; n++ {
 		now.StartOfCentury()
 	}
@@ -13,6 +16,9 @@ func BenchmarkCarbon_StartOfCentury(b *testing.B) {
 
 func BenchmarkCarbon_EndOfCentury(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().EndOfCentury()
+	}
 	for n := 0; n < b.N; n++ {
 		now.EndOfCentury()
 	}
@@ -20,6 +26,9 @@ func BenchmarkCarbon_EndOfCentury(b *testing.B) {
 
 func BenchmarkCarbon_StartOfDecade(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().StartOfDecade()
+	}
 	for n := 0; n < b.N; n++ {
 		now.StartOfDecade()
 	}
@@ -27,6 +36,9 @@ func BenchmarkCarbon_StartOfDecade(b *testing.B) {
 
 func BenchmarkCarbon_EndOfDecade(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().EndOfDecade()
+	}
 	for n := 0; n < b.N; n++ {
 		now.EndOfDecade()
 	}
@@ -34,6 +46,9 @@ func BenchmarkCarbon_EndOfDecade(b *testing.B) {
 
 func BenchmarkCarbon_StartOfYear(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().StartOfYear()
+	}
 	for n := 0; n < b.N; n++ {
 		now.StartOfYear()
 	}
@@ -41,6 +56,9 @@ func BenchmarkCarbon_StartOfYear(b *testing.B) {
 
 func BenchmarkCarbon_EndOfYear(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().EndOfYear()
+	}
 	for n := 0; n < b.N; n++ {
 		now.EndOfYear()
 	}
@@ -48,6 +66,9 @@ func BenchmarkCarbon_EndOfYear(b *testing.B) {
 
 func BenchmarkCarbon_StartOfQuarter(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().StartOfQuarter()
+	}
 	for n := 0; n < b.N; n++ {
 		now.StartOfQuarter()
 	}
@@ -55,6 +76,9 @@ func BenchmarkCarbon_StartOfQuarter(b *testing.B) {
 
 func BenchmarkCarbon_EndOfQuarter(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().EndOfQuarter()
+	}
 	for n := 0; n < b.N; n++ {
 		now.EndOfQuarter()
 	}
@@ -62,6 +86,9 @@ func BenchmarkCarbon_EndOfQuarter(b *testing.B) {
 
 func BenchmarkCarbon_StartOfMonth(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().StartOfMonth()
+	}
 	for n := 0; n < b.N; n++ {
 		now.StartOfMonth()
 	}
@@ -69,6 +96,9 @@ func BenchmarkCarbon_StartOfMonth(b *testing.B) {
 
 func BenchmarkCarbon_EndOfMonth(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().EndOfMonth()
+	}
 	for n := 0; n < b.N; n++ {
 		now.EndOfMonth()
 	}
@@ -76,6 +106,9 @@ func BenchmarkCarbon_EndOfMonth(b *testing.B) {
 
 func BenchmarkCarbon_StartOfWeek(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().StartOfWeek()
+	}
 	for n := 0; n < b.N; n++ {
 		now.StartOfWeek()
 	}
@@ -83,6 +116,9 @@ func BenchmarkCarbon_StartOfWeek(b *testing.B) {
 
 func BenchmarkCarbon_EndOfWeek(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().EndOfWeek()
+	}
 	for n := 0; n < b.N; n++ {
 		now.EndOfWeek()
 	}
@@ -90,6 +126,9 @@ func BenchmarkCarbon_EndOfWeek(b *testing.B) {
 
 func BenchmarkCarbon_StartOfDay(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().StartOfDay()
+	}
 	for n := 0; n < b.N; n++ {
 		now.StartOfDay()
 	}
@@ -97,6 +136,9 @@ func BenchmarkCarbon_StartOfDay(b *testing.B) {
 
 func BenchmarkCarbon_EndOfDay(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().EndOfDay()
+	}
 	for n := 0; n < b.N; n++ {
 		now.EndOfDay()
 	}
@@ -104,6 +146,9 @@ func BenchmarkCarbon_EndOfDay(b *testing.B) {
 
 func BenchmarkCarbon_StartOfHour(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().StartOfHour()
+	}
 	for n := 0; n < b.N; n++ {
 		now.StartOfHour()
 	}
@@ -111,6 +156,9 @@ func BenchmarkCarbon_StartOfHour(b *testing.B) {
 
 func BenchmarkCarbon_EndOfHour(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().EndOfHour()
+	}
 	for n := 0; n < b.N; n++ {
 		now.EndOfHour()
 	}
@@ -118,6 +166,9 @@ func BenchmarkCarbon_EndOfHour(b *testing.B) {
 
 func BenchmarkCarbon_StartOfMinute(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().StartOfMinute()
+	}
 	for n := 0; n < b.N; n++ {
 		now.StartOfMinute()
 	}
@@ -125,6 +176,9 @@ func BenchmarkCarbon_StartOfMinute(b *testing.B) {
 
 func BenchmarkCarbon_EndOfMinute(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().EndOfMinute()
+	}
 	for n := 0; n < b.N; n++ {
 		now.EndOfMinute()
 	}
@@ -132,6 +186,9 @@ func BenchmarkCarbon_EndOfMinute(b *testing.B) {
 
 func BenchmarkCarbon_StartOfSecond(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().StartOfSecond()
+	}
 	for n := 0; n < b.N; n++ {
 		now.StartOfSecond()
 	}
@@ -139,6 +196,9 @@ func BenchmarkCarbon_StartOfSecond(b *testing.B) {
 
 func BenchmarkCarbon_EndOfSecond(b *testing.B) {
 	now := Now()
+	for n := 0; n < b.N; n++ {
+		NewCarbon().EndOfSecond()
+	}
 	for n := 0; n < b.N; n++ {
 		now.EndOfSecond()
 	}
diff --git a/extremum_bench_test.go b/extremum_bench_test.go
index 214fd58..9471774 100755
--- a/extremum_bench_test.go
+++ b/extremum_bench_test.go
@@ -7,6 +7,12 @@ func BenchmarkCarbon_Closest(b *testing.B) {
 	for n := 0; n < b.N; n++ {
 		now.Closest(Parse("2020-08-05"), Parse("2022-08-05"))
 	}
+	for n := 0; n < b.N; n++ {
+		now.Closest(Parse("xxx"), Parse("2022-08-05"))
+	}
+	for n := 0; n < b.N; n++ {
+		now.Closest(Parse("2020-08-05"), Parse("xxx"))
+	}
 }
 
 func BenchmarkCarbon_Farthest(b *testing.B) {
@@ -14,4 +20,10 @@ func BenchmarkCarbon_Farthest(b *testing.B) {
 	for n := 0; n < b.N; n++ {
 		now.Farthest(Parse("2020-08-05"), Parse("2022-08-05"))
 	}
+	for n := 0; n < b.N; n++ {
+		now.Farthest(Parse("xxx"), Parse("2022-08-05"))
+	}
+	for n := 0; n < b.N; n++ {
+		now.Farthest(Parse("2020-08-05"), Parse("xxx"))
+	}
 }
diff --git a/tag_bench_test.go b/tag_bench_test.go
index 6b21820..c43d824 100755
--- a/tag_bench_test.go
+++ b/tag_bench_test.go
@@ -2,17 +2,13 @@ package carbon
 
 import "testing"
 
-func BenchmarkCarbon_Tag(b *testing.B) {
-	now := Now()
-	for n := 0; n < b.N; n++ {
-		now.Tag()
-	}
-}
-
 func BenchmarkCarbon_SetTag(b *testing.B) {
 	now := Now()
 	for n := 0; n < b.N; n++ {
-		now.SetTag("layout:2006-01-02")
+		now.SetTag(tag{
+			carbon: "datetime",
+			tz:     Local,
+		})
 	}
 }