Hi @Cynthia Martínez Chavarría
A similar question was asked on Spiceworks at https://community.spiceworks.com/topic/2080710-migrating-shared-calendar-to-sharepoint (answered by Bryan Gill)
- Just connect the SharePoint calendar in Outlook, (Calendar Tab, then Connect to Outlook)
- Set both calendars to the all Items view
- Ctrl+A the items from "The Calendar"
- Ctrl+V the items into the SharePoint calendar in Outlook.
- Go get coffee
- When the copy finishes, you're done!
This might be the easiest solution to what you require.
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If this is helpful please accept answer.