diff --git a/utils/paths.go b/utils/paths.go
index 42cf979..2699f88 100644
--- a/utils/paths.go
+++ b/utils/paths.go
@@ -28,10 +28,12 @@ func DBDir(home string, name string) string {
 	return filepath.Join(home, "db", fmt.Sprintf("%s.sqlite3", name))
 }
 
+const resultdirFormat = "2006-01-02T150405.999999999Z0700"
+
 // MakeResultsDir creates and returns a directory for the result
 func MakeResultsDir(home string, name string, ts time.Time) (string, error) {
 	p := filepath.Join(home, "msmts",
-		fmt.Sprintf("%s-%s", name, ts.Format(time.RFC3339Nano)))
+		fmt.Sprintf("%s-%s", name, ts.Format(resultdirFormat)))
 
 	// If the path already exists, this is a problem. It should not clash, because
 	// we are using nanosecond precision for the starttime.