diff --git a/src/org/p2pvpn/gui/Calendar.java b/src/org/p2pvpn/gui/CalendarPopup.java
similarity index 82%
rename from src/org/p2pvpn/gui/Calendar.java
rename to src/org/p2pvpn/gui/CalendarPopup.java
index 69f01c4..ebbc578 100644
--- a/src/org/p2pvpn/gui/Calendar.java
+++ b/src/org/p2pvpn/gui/CalendarPopup.java
@@ -25,6 +25,7 @@ import com.github.lgooddatepicker.optionalusertools.CalendarListener;
 import java.awt.Component;
 import java.awt.Point;
 import java.time.LocalDate;
+import java.time.LocalDateTime;
 import java.time.ZoneId;
 import java.util.Date;
 import javax.swing.JSpinner;
@@ -35,13 +36,13 @@ import javax.swing.SwingUtilities;
  * Uses internal library methods.
  * @author monsterovich
  */
-public class Calendar implements CalendarListener {
+public class CalendarPopup implements CalendarListener {
     private final CalendarPanel calendarPanel;
     private CustomPopup calendarPopup;
     private final Component parentComponent;
     private final JSpinner inputField;
     
-    public Calendar(Component component, JSpinner field) {
+    public CalendarPopup(Component component, JSpinner field) {
         parentComponent = component;
         inputField = field;
 
@@ -68,18 +69,19 @@ public class Calendar implements CalendarListener {
         calendarPanel.requestFocus();
     }
 
+    @Override
     public void selectedDateChanged(CalendarSelectionEvent event) {
         LocalDate calendarDate = event.getSource().getSelectedDate();
         if (calendarDate != null && event.isDuplicate()) {
-            Date originalDate = (Date) inputField.getModel().getValue();
-            Date date = Date.from(calendarDate.atStartOfDay(ZoneId.systemDefault()).toInstant());
-            date.setHours(originalDate.getHours());
-            date.setMinutes(originalDate.getMinutes());
-            inputField.getModel().setValue(date);
+            LocalDateTime originalDateTime = ((Date) inputField.getModel().getValue()).toInstant()
+                .atZone(ZoneId.systemDefault()).toLocalDateTime();
+            LocalDateTime newDateTime = calendarDate.atTime(originalDateTime.getHour(), originalDateTime.getMinute());
+            inputField.getModel().setValue(Date.from(newDateTime.atZone(ZoneId.systemDefault()).toInstant()));
             calendarPopup.hide();
         }
     }
     
+    @Override
     public void yearMonthChanged(YearMonthChangeEvent event) {
         
     }
diff --git a/src/org/p2pvpn/gui/InviteWindow.java b/src/org/p2pvpn/gui/InviteWindow.java
index c1e4f69..24f623b 100644
--- a/src/org/p2pvpn/gui/InviteWindow.java
+++ b/src/org/p2pvpn/gui/InviteWindow.java
@@ -39,7 +39,7 @@ import javax.swing.JMenuItem;
 import javax.swing.JOptionPane;
 import javax.swing.JPopupMenu;
 import org.p2pvpn.tools.AdvProperties;
-import org.p2pvpn.gui.Calendar;
+import org.p2pvpn.gui.CalendarPopup;
 
 /**
  * This window is shown, when the user wants to invite another persion.
@@ -50,7 +50,7 @@ public class InviteWindow extends javax.swing.JDialog implements ClipboardOwner
 
     MainControl mainControl;
     JFileChooser fileChooser;
-    Calendar calendar;
+    CalendarPopup calendarPopup;
 
 
     /**
@@ -80,7 +80,7 @@ public class InviteWindow extends javax.swing.JDialog implements ClipboardOwner
         });
         menu.add(mitem);
         txtInvitation.setComponentPopupMenu(menu);
-        calendar = new Calendar(btnCalendar, spnExpiryDate);
+        calendarPopup = new CalendarPopup(btnCalendar, spnExpiryDate);
     }
 
     /**
@@ -252,7 +252,7 @@ public class InviteWindow extends javax.swing.JDialog implements ClipboardOwner
     }// </editor-fold>//GEN-END:initComponents
 
     private void btnCalendarActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_btnCalendarActionPerformed
-        calendar.show();
+        calendarPopup.show();
     }//GEN-LAST:event_btnCalendarActionPerformed
 
     private void btnCloseActionPerformed(java.awt.event.ActionEvent evt) {// GEN-FIRST:event_btnCloseActionPerformed