diff --git a/src/MainWindow.cpp b/src/MainWindow.cpp
index e51d06e4..dde86c8b 100644
--- a/src/MainWindow.cpp
+++ b/src/MainWindow.cpp
@@ -1416,7 +1416,7 @@ void MainWindow::updatePlot(SqliteTableModel *model, bool update)
         if(xtype == QVariant::DateTime)
         {
             ui->plotWidget->xAxis->setTickLabelType(QCPAxis::ltDateTime);
-            ui->plotWidget->xAxis->setDateTimeFormat("yyyy-mm-dd");
+            ui->plotWidget->xAxis->setDateTimeFormat("yyyy-MM-dd");
         }
         else
         {