diff --git a/src/RideMetadata.cpp b/src/RideMetadata.cpp
index a5e61e67e..b5e813a1d 100644
--- a/src/RideMetadata.cpp
+++ b/src/RideMetadata.cpp
@@ -70,13 +70,13 @@ RideMetadata::configUpdate()
         Form *form;
 #ifdef ENABLE_METRICS_TRANSLATION
         if ((form = tabList.value(specialTabs.displayName(field.tab), NULL)) == NULL) {
-            form = new Form(main);
+            form = new Form(main, this);
             tabs->addTab(form, specialTabs.displayName(field.tab));
             tabList.insert(specialTabs.displayName(field.tab), form);
         }
 #else
         if ((form = tabList.value(field.tab, NULL)) == NULL) {
-            form = new Form(main);
+            form = new Form(main, this);
             tabs->addTab(form, field.tab);
             tabList.insert(field.tab, form);
         }
@@ -95,10 +95,37 @@ RideMetadata::configUpdate()
     main->notifyRideSelected(); // refresh
 }
 
+void
+RideMetadata::warnDateTime(QDateTime datetime)
+{
+    if (main->rideItem() == NULL) return;
+
+    // see if there is a ride with this date/time already?
+    // Check if an existing ride has the same starttime
+    QChar zero = QLatin1Char('0');
+    QString targetnosuffix = QString ("%1_%2_%3_%4_%5_%6")
+                           .arg(datetime.date().year(), 4, 10, zero)
+                           .arg(datetime.date().month(), 2, 10, zero)
+                           .arg(datetime.date().day(), 2, 10, zero)
+                           .arg(datetime.time().hour(), 2, 10, zero)
+                           .arg(datetime.time().minute(), 2, 10, zero)
+                           .arg(datetime.time().second(), 2, 10, zero);
+
+    // now make a regexp for all know ride types
+    foreach(QString suffix, RideFileFactory::instance().suffixes()) {
+
+        QString conflict = main->home.absolutePath() + "/" + targetnosuffix + "." + suffix;
+        if (QFile(conflict).exists() && QFileInfo(conflict).fileName() != main->rideItem()->fileName) {
+            QMessageBox::warning(this, "Date/Time Entry", "A ride already exists with that date/time, if you do not change it then you will overwrite and lose existing data");
+            return; // only warn on the first conflict!
+        }
+    }
+}
+
 /*----------------------------------------------------------------------
  * Forms (one per tab)
  *--------------------------------------------------------------------*/
-Form::Form(MainWindow *main) : main(main)
+Form::Form(MainWindow *main, RideMetadata *meta) : main(main), meta(meta)
 {
     contents = new QWidget;
     QVBoxLayout *mainLayout = new QVBoxLayout(contents);
@@ -197,7 +224,7 @@ Form::arrange()
 /*----------------------------------------------------------------------
  * Form fields
  *--------------------------------------------------------------------*/
-FormField::FormField(FieldDefinition field, MainWindow *main) : definition(field), main(main), active(false)
+FormField::FormField(FieldDefinition field, MainWindow *main, RideMetadata *meta) : definition(field), main(main), active(false), meta(meta)
 {
     QString units;
 
@@ -355,6 +382,10 @@ FormField::editFinished()
         QDateTime update = QDateTime(date, current.time());
         main->rideItem()->setStartTime(update);
         main->notifyRideSelected();
+
+        // warn if the ride already exists with that date/time
+        meta->warnDateTime(update);
+
     } else if (definition.name == "Start Time") {
         QDateTime current = main->rideItem()->ride()->startTime();
         QTime time(/* hours*/ text.mid(0,2).toInt(),
@@ -364,6 +395,10 @@ FormField::editFinished()
         QDateTime update = QDateTime(current.date(), time);
         main->rideItem()->setStartTime(update);
         main->notifyRideSelected();
+
+        // warn if the ride already exists with that date/time
+        meta->warnDateTime(update);
+
     } else {
         if (sp.isMetric(definition.name) && enabled->isChecked()) {
 
diff --git a/src/RideMetadata.h b/src/RideMetadata.h
index cf6ebc86e..99f682652 100644
--- a/src/RideMetadata.h
+++ b/src/RideMetadata.h
@@ -54,7 +54,7 @@ class FormField : public QWidget
     Q_OBJECT
 
     public:
-        FormField(FieldDefinition, MainWindow *);
+        FormField(FieldDefinition, MainWindow *, RideMetadata *meta);
         ~FormField();
         FieldDefinition definition; // define the field
         QLabel  *label;             // label
@@ -72,6 +72,7 @@ class FormField : public QWidget
         bool edited;                // value has been changed
         bool active;                // when data being changed for rideSelected
         SpecialFields sp;
+        RideMetadata *meta;
 };
 
 class KeywordCompleter : public QCompleter
@@ -110,9 +111,9 @@ class Form : public QScrollArea
     Q_OBJECT
 
     public:
-        Form(MainWindow *);
+        Form(MainWindow *, RideMetadata *meta);
         ~Form();
-        void addField(FieldDefinition x) { fields.append(new FormField(x, main)); }
+        void addField(FieldDefinition x) { fields.append(new FormField(x, main, meta)); }
         void arrange(); // the meat of the action, arranging fields on the screen
 
     private:
@@ -124,6 +125,7 @@ class Form : public QScrollArea
         QGridLayout *grid1, *grid2;
         QList<FormField*> fields; // keep track so we can destroy
         QList<QHBoxLayout *> overrides; // keep track so we can destroy
+        RideMetadata *meta;
 
 };
 
@@ -140,6 +142,7 @@ class RideMetadata : public QWidget
 
     public slots:
         void configUpdate();
+        void warnDateTime(QDateTime); // warn if file already exists after date/time changed
 
     private:
         MainWindow *main;