diff --git a/internal_logger.go b/internal_logger.go
index d0ec7ef..e497849 100644
--- a/internal_logger.go
+++ b/internal_logger.go
@@ -2,12 +2,15 @@ package flog
 
 import (
 	"io"
+	"time"
 )
 
 type internalLogger struct {
 	prefix string
 	style  string
 
+	begin time.Time
+
 	writer io.Writer
 
 	mutedAlert      bool
diff --git a/internal_logger_begin.go b/internal_logger_begin.go
index 11c9d4b..8f54fa5 100644
--- a/internal_logger_begin.go
+++ b/internal_logger_begin.go
@@ -2,6 +2,7 @@ package flog
 
 import (
 	"runtime"
+	"time"
 )
 
 func (receiver internalLogger) Begin(a ...interface{}) Logger {
@@ -16,6 +17,10 @@ func (receiver internalLogger) Begin(a ...interface{}) Logger {
 	}
 
 	logger := receiver.Prefix(funcName)
+	switch casted := logger.(type) {
+	case *internalLogger:
+		casted.begin = time.Now()
+	}
 
 	a = append([]interface{}{"BEGIN"}, a...)
 
diff --git a/internal_logger_end.go b/internal_logger_end.go
index d0160c7..8dabc9e 100644
--- a/internal_logger_end.go
+++ b/internal_logger_end.go
@@ -1,7 +1,17 @@
 package flog
 
+import (
+	"fmt"
+	"time"
+)
+
 func (receiver internalLogger) End(a ...interface{}) {
+	diff := time.Now().Sub(receiver.begin)
+
+	msg := fmt.Sprintf(" δt=%s", diff)
+
 	a = append([]interface{}{"END"}, a...)
+	a = append(a, msg)
 
 	receiver.Debug(a...)
 }