diff --git a/widgets/mainwindow.cpp b/widgets/mainwindow.cpp
index 75e8e9fe4..1fd0f2436 100644
--- a/widgets/mainwindow.cpp
+++ b/widgets/mainwindow.cpp
@@ -1635,6 +1635,7 @@ void MainWindow::dataSink(qint64 frames)
         int nsec=((n/10000)*3600) + (((n/100)%100)*60) + (n%100);
         if(!m_echoRunning) m_echoSec0=nsec;
         n=(nsec-m_echoSec0 + 864000)%86400;
+        if(n>43200) n-=86400;
         m_echoRunning=true;
         QString t;
         t = t.asprintf("%6d  %5.2f %7d %7.1f %7d %7d %7d %7.1f %7.1f",n,xlevel,