I would rather not create new calendars on iCloud because I'd have to manually sync all my events; I know I can't just drag "On my Mac" calendars into iCloud, but is there any way I can maybe export the ones stored on the hard drive and then re-import them as iCloud calendars to sync everything?
MacBook Pro 13", macOS 10.15
In iCloud section , create an event https://support.apple.com/en-in/guide/calendar/icalwr13-events/mac
And drag and drop event in the calendar of on my Mac https://support.apple.com/en-in/guide/calendar/icl1007/11.0/mac/10.15
The second method is export the event from cloud calendar ( a pop up window appears click on new folder name it and click on export , it will be exported in the location finder > documents , you can drag and drop that folder with .ics file having events in side it over the the calendar in my Mac section of calendar application .
Read this also https://support.apple.com/en-in/guide/calendar/icl1023/11.0/mac/10.15
In iCloud section , create an event https://support.apple.com/en-in/guide/calendar/icalwr13-events/mac
And drag and drop event in the calendar of on my Mac https://support.apple.com/en-in/guide/calendar/icl1007/11.0/mac/10.15
The second method is export the event from cloud calendar ( a pop up window appears click on new folder name it and click on export , it will be exported in the location finder > documents , you can drag and drop that folder with .ics file having events in side it over the the calendar in my Mac section of calendar application .
Read this also https://support.apple.com/en-in/guide/calendar/icl1023/11.0/mac/10.15
When iCloud is set up in Mac https://support.apple.com/en-in/guide/mac-help/mh36834/10.14/mac/10.14
And calendar box is turned as on in system preferences > Apple ID icon > under iCloud section , the application is automatically synced .
So whenever an event is created in calendar application of Mac https://support.apple.com/en-in/guide/calendar/icalwr13-events/mac
The calendar and its event is mirrored in iCloud.com .
I would assume that it does automatically sync, but it doesn't. There is an On My Mac section where calendars are stored only on here and another iCloud section where calendars are synced across all devices using on iCloud account. I can't drag calendars between the two categories, and am not sure how to upload On My Mac calendars to iCloud.
In the iCloud section shown in the screen shot, create a new calendar to use with the contents of the On My Mac calendar you want in iCloud. Try selecting one of your On My Mac Calendars in the Sidebar shown in your screen shot. Then Calendar/File/Export and select Export. Then Calendar/File/Import and select the newly created iCloud calendar as the import destination.
if you want to move ALL of your local calendars to iCloud, then try this:
disable the calendar sync in system preferences>iCloud, wait a few minutes and re-enable it again.
it will convert/move all local calendars to iCloud.
it will not delete your existing iCloud calendars. but maybe rename the local calendars differently before. I am not sure what it will do with duplicate calendar names (merge?).
if you only want to move a specific calendar to iCloud, then go for the export/import method as Eric wrote already.
How can I "upload" a calendar on my Macbook onto iCloud?
