Open Outlook
Go to the Calendar view
Select the calendar you want to merge from
Open the second calendar you want to combine with
Use the View tab
Choose Overlay View
Drag events from one calendar to the other if needed
Copy appointments from one calendar and paste them into the target calendar
Use the Share Calendar option if you need to merge calendars across accounts
Export one calendar to a file if needed
Import the file into the target calendar
Repeat for any additional calendars
Verify all events are in the merged calendar
