Currently there is no way to achieve this other than using two identical items with separate recurrence patterns. In the WinForms version of the control the Recurrence class provides a special event (ValidateOccurrence) that can be used to customize the individual occurrences in the pattern. For example, this event could be used to adjust the start times of certain occurrences. We can port this event to the next version of the Silverlight control.

Regards,
Meppy

Let's assume that the item and its recurrence are created like this:

var item = new Appointment();
item.StartTime = DateTime.Today;
item.EndTime = DateTime.Today;
item.HeaderText = "event";
var recurrence = new Recurrence();
recurrence.Pattern = RecurrencePattern.Daily;
recurrence.Days = 2;
recurrence.StartDate = item.StartTime;
recurrence.RecurrenceEnd = RecurrenceEnd.NumOccurrences;
recurrence.NumOccurrences = 10;
item.Recurrence = recurrence;
c.Schedule.Items.Add(item); 

Now handle the ItemClick event and 'break' the recurrence at the clicked item:

// Reschedule the recurrence from the clicked item on
var occurrence = e.Item;
if (occurrence.Recurrence != null)
{
	// First, reduce the number of occurrences of the original recurrence
	var master = occurrence.Recurrence.Master;
	var recurrence = master.Recurrence;
	master.Recurrence = null;
	recurrence.NumOccurrences = occurrence.OccurrenceIndex;
	master.Recurrence = recurrence;

	// Then clone the original item and apply a new recurrence pattern to it,
	// starting from the date of the clicked occurrence
	var newItem = master.Clone() as Appointment;
	newItem.StartTime = occurrence.StartTime;
	newItem.EndTime = occurrence.EndTime;
	newItem.Recurrence = null;
	var newRecurrence = new Recurrence();
	newRecurrence.Pattern = RecurrencePattern.Daily;
	newRecurrence.Days = 3;
	newRecurrence.StartDate = newItem.StartTime;
	newRecurrence.RecurrenceEnd = RecurrenceEnd.NumOccurrences;
	newRecurrence.NumOccurrences = 10 - occurrence.OccurrenceIndex;
	newItem.Recurrence = newRecurrence;
	c.Schedule.Items.Add(newItem);
} 

I hope this helps.

Regards,
Meppy