diff --git a/daily.cpp b/daily.cpp
index 8e01b1fd..3b86528d 100644
--- a/daily.cpp
+++ b/daily.cpp
@@ -210,6 +210,7 @@ Daily::Daily(QWidget *parent,gGraphView * shared, MainWindow *mw)
     format.setForeground(QBrush(Qt::black, Qt::SolidPattern));
     ui->calendar->setWeekdayTextFormat(Qt::Saturday, format);
     ui->calendar->setWeekdayTextFormat(Qt::Sunday, format);
+    ui->calendar->setFirstDayOfWeek(QLocale::system().firstDayOfWeek());
 
     ui->tabWidget->setCurrentWidget(ui->details);
 
diff --git a/exportcsv.cpp b/exportcsv.cpp
index 5eaa49ea..c8b16e7d 100644
--- a/exportcsv.cpp
+++ b/exportcsv.cpp
@@ -31,6 +31,9 @@ ExportCSV::ExportCSV(QWidget *parent) :
     ui->endDate->calendarWidget()->setWeekdayTextFormat(Qt::Saturday, format);
     ui->endDate->calendarWidget()->setWeekdayTextFormat(Qt::Sunday, format);
 
+    ui->startDate->calendarWidget()->setFirstDayOfWeek(QLocale::system().firstDayOfWeek());
+    ui->endDate->calendarWidget()->setFirstDayOfWeek(QLocale::system().firstDayOfWeek());
+
     // Connect the signals to update which days have CPAP data when the month is changed
     connect(ui->startDate->calendarWidget(),SIGNAL(currentPageChanged(int,int)),SLOT(startDate_currentPageChanged(int,int)));
     connect(ui->endDate->calendarWidget(),SIGNAL(currentPageChanged(int,int)),SLOT(endDate_currentPageChanged(int,int)));
diff --git a/overview.cpp b/overview.cpp
index 6058c1b4..d76f3b14 100644
--- a/overview.cpp
+++ b/overview.cpp
@@ -33,6 +33,9 @@ Overview::Overview(QWidget *parent,gGraphView * shared) :
     }
     ui->dateStart->setDisplayFormat(shortformat);
     ui->dateEnd->setDisplayFormat(shortformat);
+    ui->dateStart->calendarWidget()->setFirstDayOfWeek(QLocale::system().firstDayOfWeek());
+    ui->dateEnd->calendarWidget()->setFirstDayOfWeek(QLocale::system().firstDayOfWeek());
+
 
     // Stop both calendar drop downs highlighting weekends in red
     QTextCharFormat format = ui->dateStart->calendarWidget()->weekdayTextFormat(Qt::Saturday);