How to send automated event reminders using Zapier for events scheduled more than 30 days in advance?

I’m an event organiser

All my events details are stored in an airtable base.

I’ve created a Zap to send an SMS to my event hosts at d-1 (brief) and d+1 (debrief) 

I’m currently stuck as follows :

If the trigger is “new airtable entry” the maximum delay allowed by zapier is 1 month. Sometimes my events are booked months in advance so the delay for d day is more than 30 days > stuck

So the good trigger may be “updated record in airtable”

Let’s break this down :

The airtable entry exists, and i add a filter : “continue if the pdf file “roadbook” exists” 

1st issue, every-time i will make the smallest change into the airtable base the zap will trigger but it will be stopped by the filter > +/- ok because i will have hundreds of filtered  zap runs...

Once i add the famous roadbook file (last step of my process), the zap will run and trigger the delay step until d-1 or d+1 for the SMSs.> seems OK BUT

1st issue : this method will trigger the zap at the very slightest change in the airtable entry (i work on it on a daily basis)

2 nd issue : once the PDF roadbook is present into airtable, everytime i will make a minor change inside airtable, the zap will run once again and the recipient will receive 2-3-4-5 or more SMSs

> Stuck

If I add an airtable button “OK SMS” or even if i create an airtable automation who says “trigger zapier at event day -1” the zap wil run again and again every time i will make a change in airtable...> Stuck

Do you have an idea to help me achieve my goal ?

Thank you !