fix log output

dateconv/duration.go

@@ -0,0 +1,11 @@
+package dateconv
+
+import "time"
+
+func ParseDuration(s string) (time.Duration, error) {
+	if len(s) == 0 {
+		return time.Duration(0), nil
+	}
+
+	return time.ParseDuration(s)
+}

dateconv/duration_test.go

@@ -0,0 +1,10 @@
+package dateconv
+
+import (
+	"testing"
+)
+
+func TestParseDuration(t *testing.T) {
+	t.Log(ParseDuration(""))
+	t.Log(ParseDuration("abc"))
+}