function _setStartDateForFocus(oDate) {

		// set start date according to new focused date
		// only if focused date is not in current rendered month interval
		// new focused date should have the same position like the old one
		var oMonthsRow = this.getAggregation("monthsRow");
		var oStartDate = _getStartDate.call(this);
		var iMonth = oMonthsRow._oItemNavigation.getFocusedIndex();
		oStartDate = new CalendarDate(oDate);
		oStartDate.setMonth( oStartDate.getMonth() - iMonth);
		_setStartDate.call(this, oStartDate, false, true);

	}
@param {sap.ui.unified.calendar.CalendarDate} oDate The date which will be set to start date
@private