There are two ways you can fix this:
Adjusting Recurrence
Employee Administration -> Holiday Calendar
Highlight the reoccurrence you need to change -> Select View (KE0289)
Select the Recurrence button (KE0290)
Using the Calendar Recurrence (KE0290) screen make any needed adjustments and select Replace existing occurrence
Select OK until you have closed out of all screens.
Delete Recurrence
Employee Administration -> Holiday Calendar
Highlight the reoccurrence you need to change -> Select View (KE0289)
On the Work Day Calendar (KE0289) screen select Delete
Select DELETE to confirm you want to delete the recurrence. Select Cancel to keep the recurrence.
Select OK until you have closed out of all screens.