If you need to call someone that is notoriously busy and difficult to get a hold of: call them 5 mins before the hour.
I know that sounds crazy, but trust me it works for people who tend to be “very busy” and have less structure around their time.
This can give you 2 mins you get their attention.
Enough time to:
qualify them in or out of your sales process
share your sales micro-content to influence them to the next stage
Give it a try!