using System;

public class Program

{

​

    private void OnDateChanged(object sender, RadCalendarView.DisplayDateChangedEventArgs e)

    {

        RadCalendarView calendar = sender as RadCalendarView;          

        calendar.DisplayDateChanged -= OnDateChanged;

​

        ViewPager viewPager = GetChildrenViews<ViewPager>().First();

​

        //looks like P1 is new date, P0 is previous date;

        bool isNavigationForward = e.P1 > e.P0;

​

        DateTime dateFrom = DateTimeHelpers.FromUnixTime(e.P0);

        DateTime dateTo = DateTimeHelpers.FromUnixTime(e.P1);

​

        int shiftedByCalendarDays = (dateTo - dateFrom).Days;

​

        int viewModeStepDays = 7;

​

        int additionDaysShift = isNavigationForward

            ? viewModeStepDays

            : -viewModeStepDays;

​

        additionDaysShift -= shiftedByCalendarDays;

​

        viewPager.SetCurrentItem(viewPager.CurrentItem + additionDaysShift, true);

​

        calendar.DisplayDateChanged += OnDateChanged;

    }

}