Last Updated: 10 Jun 2024 13:25 by ADMIN

To reproduce the issue:
1. Add a RadDateTimePicker control to a Windows Forms application.
2. Use the "ar-SA" culture.
3. Attempt to manually enter a date in the RadDateTimePicker control using letters or special characters.

Dim hijriCulture As New CultureInfo("ar-SA")
hijriCulture.DateTimeFormat.Calendar = New HijriCalendar()
RadDateTimePicker1.Format = DateTimePickerFormat.Custom
RadDateTimePicker1.Culture = hijriCulture

Last Updated: 17 Apr 2024 14:39 by ADMIN
Applications hangs when using custom format containing one part ("ddd" or "dddd"). 
Last Updated: 13 Mar 2024 08:49 by ADMIN
Release 2024.1.312
Hi support,

while using the RadDateTimePicker control with FreeFormDateTime mask provider we encountered an unexpected behaviour.

While typing within the TextBox, we pressed CTRL+X to cut the inserted text to the clipboard. By doing so, a System.NullReferenceException was thrown.
Last Updated: 01 Mar 2024 12:26 by ADMIN

The selected date is 2024 Feb 29. A custom date format is applied to the control:

this.radDateTimePicker1.Format = DateTimePickerFormat.Custom;
this.radDateTimePicker1.CustomFormat = "yyyy";

When trying to change the date, an ArgumentOutOfRangeException exception is thrown.




Last Updated: 27 Feb 2024 13:02 by ADMIN
Last Updated: 19 Sep 2023 12:40 by ADMIN
In this particular case, we are using the SetToNullValue() method. To reproduce this behavior we can type a valid date in the editor area. Press the tab key to move the focus out of the control. Call the SetToNullValue() method which will set the Value property to null. Focus again on the control and type the same date again. When we tab out of the control, the date is valid and will be shown in the editor area. However, the Value property remains empty.
Last Updated: 28 Aug 2023 08:18 by ADMIN
In this scenario, the FreeFormDateTime mask type is used and the ShowCheckBox property is set to true. When the user clears the date and start type and in the process of entering the date, press Left or Right key arrows, the CheckBox inside is focused which triggers the validation of the control.
Last Updated: 23 Sep 2022 13:07 by ADMIN
Release R3 2022
To auto-select next the next parts of the RadDateTimePicker control, while typing, the AutoSelectNextPart property of the MaskDateTimeProvider needs to be set to true. We can expose this property inside the RadDateTimePicker control so that it can be set in design time.
Last Updated: 26 Jan 2022 10:26 by ADMIN
Release R1 2022 SP1
Created by: Grégory
Comments: 0
Category: DateTimePicker
Type: Bug Report

Add a RadDateTimePicker to the form and use the following code snippet:

        public RadForm1()
            RadDateTimePickerCalendar calendarBehavior = this.radDateTimePicker1.DateTimePickerElement.GetCurrentBehavior() as RadDateTimePickerCalendar;
             calendarBehavior.ShowTimePicker = true; 
            calendarBehavior.PopupControl.PopupOpening += PopupControl_PopupOpening;

       //It is fired
        private void PopupControl_PopupOpening(object sender, CancelEventArgs args)

        //It is not fired is ShowTimePicker=true
        private void radDateTimePicker1_Opening(object sender, CancelEventArgs e)

You will notice that the RadDateTimePicker.Opening event is not fired if the ShowTimePicker property is enabled.

Workaround: feel free to use the PopupControl.PopupOpening event.


Last Updated: 04 Feb 2021 14:34 by RoGro
Release R1 2021 SP1

After the installation of the latest update (Version 2021.1.122.40) for "Telerik UI for WinForms", our Formulardesigner throws a NullReferenceException during instanciating a Telerik.WinControls.UI.RadDateTimePicker.


   bei Telerik.WinControls.UI.Design.DesignTimeThemeSettingsService.GetActiveProject(_DTE dte)
   bei Telerik.WinControls.UI.Design.DesignTimeThemeSettingsService.get_ActiveProject()
   bei Telerik.WinControls.UI.Design.DesignTimeThemeSettingsService.get_Configuration()
   bei Telerik.WinControls.UI.Design.DesignTimeThemeSettingsService.Start()
   bei Telerik.WinControls.UI.Design.RadControlDesignerLite.Initialize(IComponent component)
   bei System.ComponentModel.Design.DesignerHost.AddToContainerPostProcess(IComponent component, String name, IContainer containerToAddTo)
   bei System.ComponentModel.Design.DesignerHost.PerformAdd(IComponent component, String name)
   bei System.ComponentModel.Design.DesignerHost.System.ComponentModel.Design.IDesignerHost.CreateComponent(Type componentType, String name)
   bei Formulardesigner.Loader.FormularDesignerLoader.CreateDesignerControl(IDesignerLoaderHost host, Control controlDefinition, PersistedSettings persistedSettings)

What is changed and how can we solve that?

Last Updated: 12 Oct 2020 15:11 by ADMIN
Release R3 2020 SP1
Created by: David
Comments: 4
Category: DateTimePicker
Type: Bug Report

NOTE: This is my second attempt to get a response from the support team. I am paying for Priority Support, but the ticket below has gone unanswered:


See attached screenshot. The popup calendar looks wrong when running on a display with 250% scaling. Surely, that's not correct. The calendar should not be so large and the fonts so small. Am I missing something? I have done all the other steps to enable High DPI support, and as you can see, the textbox area seems to scale fine.

Any ideas? And thanks for your help.


Last Updated: 01 Sep 2020 13:11 by ADMIN
Release R3 2020

Please use the following code snippet. The user should be allowed to resize the drop down within the specified range as it is illustrated in the gif file:

            RadDateTimePickerCalendar calBehavior = this.radDateTimePicker1.DateTimePickerElement.CurrentBehavior as RadDateTimePickerCalendar;
            calBehavior.DropDownSizingMode = SizingMode.UpDownAndRightBottom;
            calBehavior.DropDownMinSize = new Size(400, 400);
            calBehavior.DropDownMaxSize = new Size(600, 600);

Currently, the user is allowed to shrink the width, but not the height.


        public RadForm1()
            //this.radDateTimePicker1.CalendarSize = new Size(500, 500);

            RadDateTimePickerCalendar calBehavior = this.radDateTimePicker1.DateTimePickerElement.CurrentBehavior as RadDateTimePickerCalendar;
            calBehavior.DropDownSizingMode = SizingMode.UpDownAndRightBottom;
            calBehavior.DropDownMinSize = new Size(400, 400);
            calBehavior.DropDownMaxSize = new Size(600, 600);


        private void radDateTimePicker1_Opened(object sender, EventArgs e)
            RadDateTimePickerCalendar calBehavior = this.radDateTimePicker1.DateTimePickerElement.CurrentBehavior as RadDateTimePickerCalendar;
            calBehavior.PopupControl.MinimumSize= calBehavior.DropDownMinSize;

Last Updated: 03 Oct 2019 11:42 by ADMIN
Release R3 2019 SP1 (LIB 2019.3.1007)

Please refer to the attached sample project and follow the steps illustrated in the attached gif file.

Workaround: initialize a new RadDateTimePicker every time you toggle the checkbox:

    Dim location As Point
    Sub New()

        location = Me.RadDateTimePicker1.Location 
    End Sub
    Private Sub RadCheckBox1_ToggleStateChanged(sender As Object, args As Telerik.WinControls.UI.StateChangedEventArgs) Handles RadCheckBox1.ToggleStateChanged

        Me.RadDateTimePicker1 = New RadDateTimePicker()
        Me.RadDateTimePicker1.Parent = Me
        Me.RadDateTimePicker1.Location = location
        With RadDateTimePicker1
            Dim i_calendar As RadDateTimePickerCalendar = TryCast(.DateTimePickerElement.GetCurrentBehavior(), RadDateTimePickerCalendar)
            If i_calendar IsNot Nothing Then
                If args.ToggleState = Telerik.WinControls.Enumerations.ToggleState.On Then

                    i_calendar.ShowTimePicker = True
                    i_calendar.DropDownMinSize = New Size(450, 350)
                    i_calendar.DropDownMaxSize = New Size(450, 350)
                    .DateTimePickerElement.CalendarSize = New Size(450, 350)
                    .CustomFormat = "dd.MM.yyyy HH:mm" 
                    i_calendar.ShowTimePicker = False

                    i_calendar.DropDownMinSize = New Size(250, 250)
                    i_calendar.DropDownMaxSize = New Size(250, 250)
                    .DateTimePickerElement.CalendarSize = New Size(250, 250)
                    .CustomFormat = "dd.MM.yyyy"
                End If 
            End If
        End With 
    End Sub

Last Updated: 22 Jul 2019 06:07 by ADMIN

To reproduce: 

Change the scaling to 200% or larger.

Set the animation:

 this.commandBarToggleButton1.UseDefaultDisabledPaint = true;
 this.commandBarToggleButton1.Enabled = false;