To change width of vertical scrollbar or height of horizontal scrollbar used by DotNetBar for WPF CalendarView control define following resources in CalendarView.Resources:

For width of vertical scroll-bar define:

<s:CalendarView.Resources>
   <sys:Double x:Key="{x:Static SystemParameters.HorizontalScrollBarButtonWidthKey}">32</sys:Double>
</s:CalendarView.Resources>

For height of horizontal scroll-bar define:

<s:CalendarView.Resources>
   <sys:Double x:Key="{x:Static SystemParameters.VerticalScrollBarButtonHeightKey}">32</sys:Double>
</s:CalendarView.Resources>

The s: namespace refers to: xmlns:s=”clr-namespace:DevComponents.WpfSchedule;assembly=DevComponents.WpfSchedule”
The sys: namespace refers to: xmlns:sys=”clr-namespace:System;assembly=mscorlib”