If it is then a message box appears with the option to delete the calendar entry. I managed to solve this problem by watching the calendar folder for the add or change event and then see if the word " 's Birthday" or " 's Anniversary" is the subject of the Calendar entry. Delete the events you don't want, using Ctrl+Click to select a group. To check, go the Calendar and type Birthday OR Anniversary in the Search field. If the events are still linked to the Contact, Outlook will remove them from the calendar when you clear the contact. You can use Ctrl+A to select all or Ctrl+Click to select a group. Locate the Birthday: None group and drag the items to it.If another field is in the Group by box, drag it out.Right click on one of the new fields and choose Group by this field.Birthday and Anniversary are under Personal Fields. In other versions, you can right click on the row of field names and choose Field Chooser. In Outlook 2010, do this from View ribbon, View setting. Add the Birthday and Anniversary field to the view.
This video shows you how to use a group by view to remove dates from Contacts and use Instant Search to find Birthday and Anniversary events on your calendar. Hold Shift as you select the first and last items to delete a group of events at once. Removing the dates from the calendar is simple: initiate a search for Birthday OR Anniversary and delete the items with those words in the subject. (Syncing with a device will often break the link). However, its easy to break the link which will prevent Outlook from breaking the link. If the Contacts and Events are still linked, Outlook will delete the birthday or anniversary event when you remove the date from the Contact. You can hold Shift as you select as group of Contacts, which will speed the process up if you have a lot of contacts. If you want to remove the dates quickly and (fairly) easily, use a group by view, grouping by the Birthday or Anniversary field then drag the contacts to the None field. It's not 100% fool-proof and may not prevent every birthday from being added to the calendar, but it should delete most additions. However, if you want to use the birthday field, you can use a macro to remove the birthday event from the calendar.