diff --git a/src/declarativeimports/calendar/calendar.h b/src/declarativeimports/calendar/calendar.h
--- a/src/declarativeimports/calendar/calendar.h
+++ b/src/declarativeimports/calendar/calendar.h
@@ -32,17 +32,23 @@
 class Calendar : public QObject
 {
     Q_OBJECT
+    /* The conversion between QDate and JS Date is broken. The specification says that a date
+     * is represented by the start of the UTC day, but for negative to UTC timezones this results
+     * in wrong dates: Jan 2 in C++ -> Jan 2 (00:00) UTC -> Jan 1 (23:00) UTC-1 in JS.
+     * So use QDateTime for interfacing to always carry a timezone around.
+     * https://bugreports.qt.io/browse/QTBUG-29328 */
+
     /**
      * This property is used to determine which data from which month to show, it ensures
      * the day passed in the QDate is visible
      */
-    Q_PROPERTY(QDate displayedDate READ displayedDate WRITE setDisplayedDate NOTIFY displayedDateChanged)
+    Q_PROPERTY(QDateTime displayedDate READ displayedDate WRITE setDisplayedDate NOTIFY displayedDateChanged)
 
     /**
      * This property is used to determine which data from which month to show, it ensures
      * the day passed in the QDate is visible
      */
-    Q_PROPERTY(QDate today READ today WRITE setToday NOTIFY todayChanged)
+    Q_PROPERTY(QDateTime today READ today WRITE setToday NOTIFY todayChanged)
 
     /**
      * This determines which kind of data types should be contained in
@@ -140,12 +146,13 @@
     explicit Calendar(QObject *parent = nullptr);
 
     // Displayed date
-    QDate displayedDate() const;
+    QDateTime displayedDate() const;
     void setDisplayedDate(const QDate &dateTime);
+    void setDisplayedDate(const QDateTime &dateTime);
 
     // The day that represents "today"
-    QDate today() const;
-    void setToday(const QDate &dateTime);
+    QDateTime today() const;
+    void setToday(const QDateTime &dateTime);
 
     // Types
     int types() const;
diff --git a/src/declarativeimports/calendar/calendar.cpp b/src/declarativeimports/calendar/calendar.cpp
--- a/src/declarativeimports/calendar/calendar.cpp
+++ b/src/declarativeimports/calendar/calendar.cpp
@@ -39,9 +39,9 @@
 //   connect(m_dayHelper, SIGNAL(calendarChanged()), this, SLOT(updateData()));
 }
 
-QDate Calendar::displayedDate() const
+QDateTime Calendar::displayedDate() const
 {
-    return m_displayedDate;
+    return QDateTime(m_displayedDate);
 }
 
 void Calendar::setDisplayedDate(const QDate &dateTime)
@@ -67,18 +67,24 @@
     }
 }
 
-QDate Calendar::today() const
+void Calendar::setDisplayedDate(const QDateTime &dateTime)
 {
-    return m_today;
+    setDisplayedDate(dateTime.date());
 }
 
-void Calendar::setToday(const QDate &dateTime)
+QDateTime Calendar::today() const
 {
-    if (dateTime == m_today) {
+    return QDateTime(m_today);
+}
+
+void Calendar::setToday(const QDateTime &dateTime)
+{
+    QDate date = dateTime.date();
+    if (date == m_today) {
         return;
     }
 
-    m_today = dateTime;
+    m_today = date;
     if (m_displayedDate.isNull()) {
         resetToToday();
     } else {