One of the reasons I haven't implemented Calendar files enmasse within my organisation is that they have to be opened & proof read each time a program is cloned. I worry that people will forget this & have prospects add old calendar events to their calendars, so instead I make them create a new one for each event.
I would prefer instead a strong link between the Schedule's time/date as defined at the event level. Through to the Calendar file's schedule. Additionally I'd like to available as a token that I can use standardly in emails.
Then you can use flowsteps to say, wait until 1 day before {{Event.Start}} ... three days later, wait until 30 minutes after {{Event.End}}