diff --git a/src/dialogs/expirydialog.cpp b/src/dialogs/expirydialog.cpp
index f12d5c0a6..e3e477f5b 100644
--- a/src/dialogs/expirydialog.cpp
+++ b/src/dialogs/expirydialog.cpp
@@ -1,335 +1,314 @@
 /* -*- mode: c++; c-basic-offset:4 -*-
     dialogs/expirydialog.cpp
 
     This file is part of Kleopatra, the KDE keymanager
     SPDX-FileCopyrightText: 2008 Klarälvdalens Datakonsult AB
     SPDX-FileCopyrightText: 2021 g10 Code GmbH
     SPDX-FileContributor: Ingo Klöcker <dev@ingo-kloecker.de>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #include <config-kleopatra.h>
 
 #include "expirydialog.h"
 
 #include "utils/qt-cxx20-compat.h"
 
+#include <KDateComboBox>
 #include <KLocalizedString>
 #include <KStandardGuiItem>
 
-#include <QCalendarWidget>
 #include <QCheckBox>
 #include <QComboBox>
 #include <QDate>
 #include <QDialogButtonBox>
 #include <QHBoxLayout>
 #include <QLabel>
 #include <QPushButton>
 #include <QRadioButton>
 #include <QSpinBox>
 #include <QVBoxLayout>
 
 using namespace Kleo;
 using namespace Kleo::Dialogs;
 
 namespace
 {
 
 enum Period {
     Days,
     Weeks,
     Months,
     Years,
 
     NumPeriods
 };
 
 static QDate date_by_amount_and_unit(int inAmount, int inUnit)
 {
     const QDate current = QDate::currentDate();
     switch (inUnit) {
     case Days:   return current.addDays(inAmount);
     case Weeks:  return current.addDays(7 * inAmount);
     case Months: return current.addMonths(inAmount);
     case Years:  return current.addYears(inAmount);
     default:
         Q_ASSERT(!"Should not reach here");
     }
     return QDate();
 }
 
 // these calculations should be precise enough for the forseeable future...
 static const double DAYS_IN_GREGORIAN_YEAR = 365.2425;
 
 static int monthsBetween(const QDate &d1, const QDate &d2)
 {
     const int days = d1.daysTo(d2);
     return qRound(days / DAYS_IN_GREGORIAN_YEAR * 12);
 }
 
 static int yearsBetween(const QDate &d1, const QDate &d2)
 {
     const int days = d1.daysTo(d2);
     return qRound(days / DAYS_IN_GREGORIAN_YEAR);
 }
 
-auto radioButtonSize(const QRadioButton *radioButton)
-{
-    QStyleOptionButton opt;
-    return radioButton->style()->sizeFromContents(QStyle::CT_RadioButton, &opt, QSize(), radioButton);
-}
-
 }
 
 class ExpiryDialog::Private
 {
     friend class ::Kleo::Dialogs::ExpiryDialog;
     ExpiryDialog *const q;
 public:
     explicit Private(Mode mode, ExpiryDialog *qq)
         : q{qq}
         , mode{mode}
         , inUnit{Days}
         , ui{mode, q}
     {
 #if QT_DEPRECATED_SINCE(5, 14)
         connect(ui.inSB, qOverload<int>(&QSpinBox::valueChanged),
                 q, [this] () { slotInAmountChanged(); });
 #else
         connect(ui.inSB, &QSpinBox::valueChanged,
                 q, [this] () { slotInAmountChanged(); });
 #endif
         connect(ui.inCB, qOverload<int>(&QComboBox::currentIndexChanged),
                 q, [this] () { slotInUnitChanged(); });
-        connect(ui.onCW, &QCalendarWidget::selectionChanged,
+        connect(ui.onCB, &KDateComboBox::dateChanged,
                 q, [this] () { slotOnDateChanged(); });
-        connect(ui.onCW, &QCalendarWidget::currentPageChanged,
-                q, [this] (int year, int month) {
-                    // We select the same day in the month when
-                    // a page is switched.
-                    auto date = ui.onCW->selectedDate();
-                    if (!date.setDate(year, month, date.day())) {
-                        date.setDate(year, month, 1);
-                    }
-                    ui.onCW->setSelectedDate(date);
-                });
 
         Q_ASSERT(ui.inCB->currentIndex() == inUnit);
     }
 
 private:
     void slotInAmountChanged();
     void slotInUnitChanged();
     void slotOnDateChanged();
 
 private:
     QDate inDate() const;
     int inAmountByDate(const QDate &date) const;
 
 private:
     ExpiryDialog::Mode mode;
     int inUnit;
 
     struct UI {
         QRadioButton *neverRB;
         QRadioButton *inRB;
         QSpinBox *inSB;
         QComboBox *inCB;
         QRadioButton *onRB;
-        QCalendarWidget *onCW;
+        KDateComboBox *onCB;
         QCheckBox *updateSubkeysCheckBox;
 
         explicit UI(Mode mode, Dialogs::ExpiryDialog *qq)
         {
             auto mainLayout = new QVBoxLayout{qq};
 
             auto mainWidget = new QWidget{qq};
 
             auto vboxLayout = new QVBoxLayout{mainWidget};
             vboxLayout->setContentsMargins(0, 0, 0, 0);
 
             {
                 auto label = new QLabel{qq};
                 label->setText(mode == Mode::UpdateIndividualSubkey ?
                                i18n("Please select when to expire this subkey:") :
                                i18n("Please select when to expire this certificate:"));
                 vboxLayout->addWidget(label);
             }
 
             neverRB = new QRadioButton(i18n("Ne&ver"), mainWidget);
             neverRB->setChecked(false);
 
             vboxLayout->addWidget(neverRB);
 
             {
                 auto hboxLayout = new QHBoxLayout;
 
                 inRB = new QRadioButton{i18n("In"), mainWidget};
                 inRB->setChecked(false);
 
                 hboxLayout->addWidget(inRB);
 
                 inSB = new QSpinBox{mainWidget};
                 inSB->setEnabled(false);
                 inSB->setAlignment(Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter);
                 inSB->setMinimum(1);
 
                 hboxLayout->addWidget(inSB);
 
                 inCB = new QComboBox{mainWidget};
                 inCB->addItem(i18n("Days"));
                 inCB->addItem(i18n("Weeks"));
                 inCB->addItem(i18n("Months"));
                 inCB->addItem(i18n("Years"));
                 Q_ASSERT(inCB->count() == NumPeriods);
                 inCB->setEnabled(false);
 
                 hboxLayout->addWidget(inCB);
 
                 hboxLayout->addStretch(1);
 
                 vboxLayout->addLayout(hboxLayout);
             }
 
-            onRB = new QRadioButton{i18n("On this da&y:"), mainWidget};
-            onRB->setChecked(true);
-
-            vboxLayout->addWidget(onRB);
-
             {
                 auto hboxLayout = new QHBoxLayout;
 
-                hboxLayout->addSpacing(radioButtonSize(onRB).width());
+                onRB = new QRadioButton{i18n("On this da&y:"), mainWidget};
+                onRB->setChecked(true);
+
+                hboxLayout->addWidget(onRB);
 
-                onCW = new QCalendarWidget{mainWidget};
-                onCW->setGridVisible(true);
-                onCW->setMinimumDate(QDate::currentDate().addDays(1));
+                onCB = new KDateComboBox{mainWidget};
+                onCB->setMinimumDate(QDate::currentDate().addDays(1));
 
-                hboxLayout->addWidget(onCW);
+                hboxLayout->addWidget(onCB);
 
                 hboxLayout->addStretch(1);
 
                 vboxLayout->addLayout(hboxLayout);
             }
 
             {
                 updateSubkeysCheckBox = new QCheckBox{i18n("Also update the expiry of the subkeys"), qq};
 #ifdef QGPGME_SUPPORTS_CHANGING_EXPIRATION_OF_COMPLETE_KEY
                 updateSubkeysCheckBox->setVisible(mode == Mode::UpdateCertificateWithSubkeys);
 #else
                 updateSubkeysCheckBox->setVisible(false);
 #endif
                 vboxLayout->addWidget(updateSubkeysCheckBox);
             }
 
             vboxLayout->addStretch(1);
 
             mainLayout->addWidget(mainWidget);
 
             auto buttonBox = new QDialogButtonBox{QDialogButtonBox::Ok | QDialogButtonBox::Cancel, qq};
             auto okButton = buttonBox->button(QDialogButtonBox::Ok);
             KGuiItem::assign(okButton, KStandardGuiItem::ok());
             okButton->setDefault(true);
             okButton->setShortcut(Qt::CTRL | Qt::Key_Return);
             KGuiItem::assign(buttonBox->button(QDialogButtonBox::Cancel), KStandardGuiItem::cancel());
             qq->connect(buttonBox, &QDialogButtonBox::accepted, qq, &QDialog::accept);
             qq->connect(buttonBox, &QDialogButtonBox::rejected, qq, &QDialog::reject);
 
             mainLayout->addWidget(buttonBox);
 
-            connect(onRB, &QRadioButton::toggled, onCW, &QWidget::setEnabled);
+            connect(onRB, &QRadioButton::toggled, onCB, &QWidget::setEnabled);
             connect(inRB, &QRadioButton::toggled, inCB, &QWidget::setEnabled);
             connect(inRB, &QRadioButton::toggled, inSB, &QWidget::setEnabled);
         }
     } ui;
 };
 
 void ExpiryDialog::Private::slotInUnitChanged()
 {
     const int oldInAmount = ui.inSB->value();
     const QDate targetDate = date_by_amount_and_unit(oldInAmount, inUnit);
     inUnit = ui.inCB->currentIndex();
     if (targetDate.isValid()) {
         ui.inSB->setValue(inAmountByDate(targetDate));
     } else {
         slotInAmountChanged();
     }
 }
 
 void ExpiryDialog::Private::slotInAmountChanged()
 {
-    // Only modify onCW when onCW is slave:
     if (ui.inRB->isChecked()) {
-        ui.onCW->setSelectedDate(inDate());
+        ui.onCB->setDate(inDate());
     }
 }
 
 void ExpiryDialog::Private::slotOnDateChanged()
 {
-    // Only modify inSB/inCB when onCW is master:
     if (ui.onRB->isChecked()) {
-        ui.inSB->setValue(inAmountByDate(ui.onCW->selectedDate()));
+        ui.inSB->setValue(inAmountByDate(ui.onCB->date()));
     }
 }
 
 QDate ExpiryDialog::Private::inDate() const
 {
     return date_by_amount_and_unit(ui.inSB->value(), ui.inCB->currentIndex());
 }
 
 int ExpiryDialog::Private::inAmountByDate(const QDate &selected) const
 {
     const QDate current  = QDate::currentDate();
 
     switch (ui.inCB->currentIndex()) {
     case Days:   return current.daysTo(selected);
     case Weeks:  return qRound(current.daysTo(selected) / 7.0);
     case Months: return monthsBetween(current, selected);
     case Years:  return yearsBetween(current, selected);
     };
     Q_ASSERT(!"Should not reach here");
     return -1;
 }
 
 ExpiryDialog::ExpiryDialog(Mode mode, QWidget *p)
     : QDialog{p}
     , d{new Private{mode, this}}
 {
     setWindowTitle(i18nc("@title:window", "Change Expiry"));
 }
 
 ExpiryDialog::~ExpiryDialog() = default;
 
 void ExpiryDialog::setDateOfExpiry(const QDate &date)
 {
     const QDate current = QDate::currentDate();
     if (date.isValid()) {
         d->ui.onRB->setChecked(true);
-        d->ui.onCW->setSelectedDate(qMax(date, current));
+        d->ui.onCB->setDate(qMax(date, current));
     } else {
         d->ui.neverRB->setChecked(true);
-        d->ui.onCW->setSelectedDate(current);
+        d->ui.onCB->setDate(current);
         d->ui.inSB->setValue(0);
     }
 }
 
 QDate ExpiryDialog::dateOfExpiry() const
 {
     return
         d->ui.inRB->isChecked() ? d->inDate() :
-        d->ui.onRB->isChecked() ? d->ui.onCW->selectedDate() :
+        d->ui.onRB->isChecked() ? d->ui.onCB->date() :
         QDate{};
 }
 
 void ExpiryDialog::setUpdateExpirationOfAllSubkeys(bool update)
 {
     d->ui.updateSubkeysCheckBox->setChecked(update);
 }
 
 bool ExpiryDialog::updateExpirationOfAllSubkeys() const
 {
     return d->ui.updateSubkeysCheckBox->isChecked();
 }
 
 #include "moc_expirydialog.cpp"