diff --git a/widgets/mainwindow.cpp b/widgets/mainwindow.cpp
index d6d83ea24..16af8a29c 100644
--- a/widgets/mainwindow.cpp
+++ b/widgets/mainwindow.cpp
@@ -1443,6 +1443,7 @@ void MainWindow::dataSink(qint64 frames)
     dec_data.params.ndiskdat=1;
   } else {
     dec_data.params.ndiskdat=0;
+    m_wideGraph->setDiskUTC(-1);
   }
 
   m_bUseRef=m_wideGraph->useRef();
@@ -2864,6 +2865,7 @@ void MainWindow::on_actionDecode_remaining_files_in_directory_triggered()
 
 void MainWindow::diskDat()                                   //diskDat()
 {
+  m_wideGraph->setDiskUTC(dec_data.params.nutc);
   if(dec_data.params.kin>0) {
     int k;
     int kstep=m_FFTSize;
diff --git a/widgets/plotter.cpp b/widgets/plotter.cpp
index 557196ca9..3b8daa9cd 100644
--- a/widgets/plotter.cpp
+++ b/widgets/plotter.cpp
@@ -246,13 +246,24 @@ void CPlotter::draw(float swide[], bool bScroll, bool bRed)
   if(m_line == painter1.fontMetrics ().height ()) {
     painter1.setPen(Qt::white);
     QString t;
-    qint64 ms = QDateTime::currentMSecsSinceEpoch() % 86400000;
-    int n = fmod(0.001*ms,m_TRperiod);
-    QDateTime t1=QDateTime::currentDateTimeUtc().addSecs(-n);
-    if(m_TRperiod<60.0) {
-      t=t1.toString("hh:mm:ss") + "    " + m_rxBand;
+    if(m_nUTC<0) {
+      qint64 ms = QDateTime::currentMSecsSinceEpoch() % 86400000;
+      int n = fmod(0.001*ms,m_TRperiod);
+      QDateTime t1=QDateTime::currentDateTimeUtc().addSecs(-n);
+      if(m_TRperiod<60.0) {
+        t=t1.toString("hh:mm:ss") + "    " + m_rxBand;
+      } else {
+        t=t1.toString("hh:mm") + "    " + m_rxBand;
+      }
     } else {
-      t=t1.toString("hh:mm") + "    " + m_rxBand;
+      int ih=m_nUTC/10000;
+      int im=(m_nUTC - 10000*ih)/100;
+      int is=m_nUTC%100;
+      if(m_TRperiod<60) {
+        t.sprintf("%02d:%02d:%02d",ih,im,is) + "    " + m_rxBand;
+      } else {
+        t.sprintf("%02d:%02d",ih,im) + "    " + m_rxBand;
+      }
     }
     painter1.drawText (5, painter1.fontMetrics ().ascent (), t);
   }
@@ -882,3 +893,8 @@ void CPlotter::setRedFile(QString fRed)
 {
   m_redFile=fRed;
 }
+
+void CPlotter::setDiskUTC(int nutc)
+{
+  m_nUTC=nutc;
+}
diff --git a/widgets/plotter.h b/widgets/plotter.h
index 582d36451..52936f2b8 100644
--- a/widgets/plotter.h
+++ b/widgets/plotter.h
@@ -87,6 +87,7 @@ public:
   void setRedFile(QString fRed);
   void setFST4_FreqRange(int fLow,int fHigh);
   void setSingleDecode(bool b);
+  void setDiskUTC(int nutc);
 
   bool scaleOK () const {return m_bScaleOK;}
 signals:
@@ -136,6 +137,7 @@ private:
   qint32  m_ib;
   qint32  m_nfa;
   qint32  m_nfb;
+  qint32  m_nUTC;
 
   QPixmap m_WaterfallPixmap;
   QPixmap m_2DPixmap;
diff --git a/widgets/widegraph.cpp b/widgets/widegraph.cpp
index bb53279cd..edb81c2f0 100644
--- a/widgets/widegraph.cpp
+++ b/widgets/widegraph.cpp
@@ -542,3 +542,8 @@ void WideGraph::setRedFile(QString fRed)
 {
   ui->widePlot->setRedFile(fRed);
 }
+
+void WideGraph::setDiskUTC(int nutc)
+{
+  ui->widePlot->setDiskUTC(nutc);
+}
diff --git a/widgets/widegraph.h b/widgets/widegraph.h
index 421fc8213..e8d241daf 100644
--- a/widgets/widegraph.h
+++ b/widgets/widegraph.h
@@ -51,6 +51,7 @@ public:
   void   setRedFile(QString fRed);
   void   setFST4_FreqRange(int fLow,int fHigh);
   void   setSingleDecode(bool b);
+  void   setDiskUTC(int nutc);
 
 signals:
   void freezeDecode2(int n);