how to create a repeating event in Automator?
I was unable to get all the way to my ultimate goal of creating repeating calendar events with open file alerts.  But, i did at least solve this question of how to create a repeating calendar event in AppleScript, so here it is.
The main issue is that you can't actually create a repeating event.  You have to create a static event, then modify that event to repeat.  Here's the code that is working for me:
#Event name &amp; description
set title to &quot;event title&quot;
set taskDescription to &quot;The Description&quot;

# which dates to use?
set startDate to date (&quot;07/21/2020&quot;)
set endDate to date (&quot;07/21/2020&quot;) -- last date to include

# which calendars contain the events?
set thisCalendar to &quot;Automator&quot;

# how many days in between repeats?
set interval to 2

tell application &quot;Calendar&quot;
    tell calendar thisCalendar
        make new event at end with properties {description:taskDescription, summary:title, start date:startDate + 540 * minutes, end date:startDate + 540 * minutes} # creates event at 9am, modify to suit.
        set theEvents to (every event where its start date is equal to startDate + 540 * minutes)
        set recurrence of item 1 of theEvents to &quot;FREQ=DAILY;INTERVAL=&quot; &amp; interval
    end tell
end tell

If you don't have a local calendar called &quot;Automator&quot;, then this might give you problems, I'm not sure.  Feel free to change the calendar name if needed.