SharePoint recurring events - How to set end date for "Meeting with no end date"

I have created sync utility for copying meeting from Outlook to SharePoint calender. Issue is with recurring meetings with no end date.In brief, for any recurring meeting i create recurrence pattern e.g.

<recurrence><rule><firstDayOfWeek>su</firstDayOfWeek><firstDayOfWeek>su</firstDayOfWeek><repeat><weekly tu="TRUE"  weekFrequency="1" /></repeat><repeatForever>FALSE</repeatForever></rule></recurrence>

For calender item to get updated, I have to specify start date and end date. Start date is obtained from Outlook meeting first occurence. But last occurence is null. So how to update sharePoint item (as End Date is mandatory field for calendar list).

In case of manual event creation in Calendar list, its observed that sharepoint automatically sets end date for some predefinate occurences.