I am new to WPF. I want to use datetime picker. I have downloaded the \"Extended WPF Toolkit - 1.9.0\" from below site.
http://wpftoolkit.codeplex.com/releases/view/9697
In XAML you should add:
For AvalonDock:
xmlns:xcad="http://schemas.xceed.com/wpf/xaml/avalondock"
For WPF Toolkit:
xmlns:xctk="http://schemas.xceed.com/wpf/xaml/toolkit"