If a Recurring Shift results in a shift falling on a day where the actual shift is different, such as a Bank Holiday, then a Shift Exception can be created. If no shift is required on this day then use a Shift Exclusion instead.
Create the exception shift by Adding a New Shift then select the Exception to Existing Shift option.
In the drop box that appears below the Exception, select the Shift to which this is an exception.
Select 
to save the Exception shift.
On this day, the original shift will be removed and replaced by the Exception shift. In the example above this means that the rucurring shift 'Day Shift' that would have appeared on 05/05/2014 will be removed from the recurrence and the shift 'Bank Holiday Day Shift' will be presented to the user instead.