1. Confirm that you have a good backup
2. Create a static, action query filtering on Action Date = X
3. On the navigation bar, click Admin and select Global Change Records
4. Highlight Action and click New Change
5. Click the Include button and indicate selected records and the query that you created in step number 2
6. Select Action Date and change the operator to Replace
7. Indicate the incorrect value (X) and in the replace with window indicate the correct value Y
8. Clicking the Change Now button will start the process