How do I retrieve missing iCal notes on MacBook Air?

1. Make sure your Calendar list is visible

Sometimes the notes are still there, but the calendar containing them is hidden from view:

1. Open the Calendar app on your Mac.
2. Click View > Show Calendar List (or click the small sidebar icon in the top-left corner).
3. Ensure the checkboxes next to all of your listed calendars (under iCloud, On My Mac, or other accounts) are checked.

2. Verify account syncing

If your events and event notes are stored in iCloud or another account (like Google or Yahoo):

1. Open System Settings > Apple Account (click your name at the top).
2. Go to iCloud > Saved to iCloud (or Apps Using iCloud).
3. Ensure Calendar is turned ON. If it is already on, toggle it off, wait 10 seconds, and turn it back on to force a sync.
4. If you use a non-Apple account (like Gmail), go to System Settings > Internet Accounts, select your account, and confirm Calendars is checked.

3. Restore an archived backup from iCloud.com

If the calendar notes were deleted, Apple automatically archives snapshots of your calendars on iCloud:

1. Go to icloud.com in Safari and sign in with your Apple Account.
2. Click the square menu icon in the top right and select Data Recovery (or Account Settings > Restore Calendars).
3. Click Restore Calendars.
4. Find an archive date from before your notes disappeared and click Restore. This will push that saved version back to your MacBook Air.

Note: If you were looking for standalone notes rather than calendar event notes, open the Notes app on your Mac and check the Recently Deleted folder in the left sidebar, or verify that Notes is enabled under System Settings > Apple Account > iCloud.