@Daveken 

How are people booking the call? Is there a reason you’re not using that for reminders, etc? What is your ultimate goal for using Klaviyo instead of the platform they book through, or just adding them a calendar event and adding the reminders there?
 

The only way to trigger based on a specific time is if you send them as events as mentioned in the other post you referred to. 

And the issue with events is that once they are submitted, they cannot be changed, so as you said… it will be fragile in terms of cancellations, reschedules, etc. You would have to send over different events as discussed here. Doesn’t seem worth all the work. 

@Jessica eCommerce Badassery People are booking the call through an app developed by a 3rd party. They’re already posting booking events to Klaviyo, so the hope was to reduce extra dev time by just sending reminders from Klaviyo based on that event.  It’s also generally nice to have communication centralized.

But yeah, think our workaround will be to have them emit an event at X amount(s) of time prior to a call.