It sounds like you want to have your one off event type creation macro perpetually allow for scheduling between the current day and the next two months? If that’s the case you would need to update the date range daily, setting start_date to the current day and end_date to the current day + two months.

It looks like Espanso supports the concept of an offset regarding dates: https://espanso.org/docs/matches/extensions/#future-and-past-dates

So you would replace your “start_date” field with whatever you are replacing with “today” and replace “end_date” field with the 2 month offset from “today” with whatever you call your trigger.

I believe it would look something like this but might take some trial and error

curl --request POST \
  --url https://api.calendly.com/one_off_event_types \
  --header 'Authorization: Bearer <myapikey>' \
  --header 'Content-Type: application/json' \
  --data '{
    "name": "15 Minute Meeting",
    "host": "https://api.calendly.com/users/<myhostlink>",
    "duration": 15,
    "timezone": "Europe/Dublin",
    "date_setting": {
      "type": "date_range",
      "start_date": ":today",
      "end_date": ":two_months"
    }
  }'