It should be working as you describe, i.e. it will scroll to the set position after the initial page load. The default value is set to BusinessBeginsHour and you can override it as needed:
<%=Html.DayPilotCalendar("dpc", new DayPilotCalendarConfig(Silver.Theme)
{
ViewType = DayPilot.Web.Mvc.Enums.Calendar.ViewType.Week,
BackendUrl = ResolveUrl("~/Calendar/Backend"),
ScrollPositionHour = 10
})%>
It seems to work fine in the demo.
The problem may be the if the Calendar is not visible during initialization (e.g. it's placed on a tab which is hidden) then the scrollbar position update has no effect (that's a browser limitation).
You can fix it by calling:
dpc.enableScrolling();
You can also set the scrollbar position directly (in pixels):
dpc.nav.scroll.scrollTop = 9 * dpc.cellHeight + 1;
Please let me know if it still doesn't work.