How to change the width of the WinForms DateTimePicker (DateTimePickerAdv) when it is set to custom format?

this.dateTimePickerAdv3.ShowCheckBox = false;
this.dateTimePickerAdv3.ShowUpDown = true;
this.dateTimePickerAdv3.AutoSize = false;
this.dateTimePickerAdv3.AutoSizeMode = AutoSizeMode.GrowOnly;
this.dateTimePickerAdv3.Format = DateTimePickerFormat.Custom;
this.dateTimePickerAdv3.CustomFormat = "dd/MMM";
int updownWidth = 0, dropWidth = 0;
 
foreach (Control ctrl in this.dateTimePickerAdv3.Controls)
{
   if (ctrl.GetType().ToString() == "Syncfusion.Windows.Forms.Tools.DateTimePickerUpDownButton")
     updownWidth = ctrl.Size.Width;
   else if (ctrl.GetType().ToString() == "Syncfusion.Windows.Forms.Tools.DateTimePickerDropButton")
     dropWidth = ctrl.Size.Width;
}
 
//Sum up the width of drop down button, updown button and font.
int nWidth = dropWidth + updownWidth + Convert.ToInt32(this.dateTimePickerAdv3.Font.Size *
this.dateTimePickerAdv3.Value.ToString(this.dateTimePickerAdv3.CustomFormat).Length);
this.dateTimePickerAdv3.Width = nWidth;

Me.dateTimePickerAdv3.ShowCheckBox = False
Me.dateTimePickerAdv3.ShowUpDown = True
Me.dateTimePickerAdv3.AutoSize = False
Me.dateTimePickerAdv3.AutoSizeMode = AutoSizeMode.GrowOnly
Me.dateTimePickerAdv3.Format = DateTimePickerFormat.Custom
Me.dateTimePickerAdv3.CustomFormat = "dd/MMM"
Dim updownWidth As Integer = 0, dropWidth As Integer = 0
 
For Each ctrl As Control In Me.dateTimePickerAdv3.Controls
   If ctrl.GetType().ToString() = "Syncfusion.Windows.Forms.Tools.DateTimePickerUpDownButton" Then
     updownWidth = ctrl.Size.Width
   Else If ctrl.GetType().ToString() = "Syncfusion.Windows.Forms.Tools.DateTimePickerDropButton" Then
     dropWidth = ctrl.Size.Width
   End If
Next ctrl
 
''Sum up the width of drop down button, updown button and font.
Dim nWidth As Integer = dropWidth + updownWidth + Convert.ToInt32(Me.dateTimePickerAdv3.Font.Size * Me.dateTimePickerAdv3.Value.ToString(Me.dateTimePickerAdv3.CustomFormat).Length)
Me.dateTimePickerAdv3.Width = nWidth