iCloud repeatedly deleting all my events, even after a restore

DeepSeek repeatedly failed on a similar script for BusyCal, but refused to acknowledge it. BusyCal officially does not support AppleScript, though the app has an AppleScript dictionary. ChatGPT-4o eventually admitted failure:

The BusyCal AppleScript dictionary is misleading, and even though it defines a command like:

applescript
CopyEdit
fetch calendar events from <date> to <date>

…it does not actually compile in standard AppleScript syntax, and many users have found it broken or non-functional despite being documented. 

Summary: BusyCal AppleScript Event Access Is Broken

• every event of calendar → ❌ not supported
• events between X and Y → ❌ causes syntax error
• fetch calendar events from X to Y → ❌ declared in dictionary, but does not compile

Another BusyCal bug:  Exporting a calendar with a lot of Cal.app-only duplicates, creating a new iCloud calendar in BusyCal, and then importing lost a small proportion of records in one calendar, as revealed by the BBEdit/BeyondCompare procedure below.  I don’t have an exact number, but there were 2112 events including duplicates, 1076 in the synced calendar; I found five missing events after getting about a tenth of the way through the BeyondCompare display of diffs with context.  All had meeting invitees.

I believe the BusyCal documentation warns about losing invitees when moving a calendar between local storage and iCloud, which might be related, so my next step is to try the same process, but creating the new calendar in  Calendar.app.

Importing a different .ics file from  Cal to BusyCal seemed to create duplicates in BusyCal. Before the import, Cal on my main machine reported 499 events, with only one in BusyCal, and 27 in Cal on my secondary Mac. After the import, List View in BusyCal reported 1600 events (1471 after removing duplicates), and Cal reported 968, with 495 in Cal on my secondary Mac.

That gave, on the remote Mac, somewhat different missing events, e.g. 8/10/18 1:05pm. 1076 total on main Mac; remote Mac, first method 1069, second 1065.