Automation triggered X hours ahead of appointment time

[airyfairy]

I run an appointment system on Airtable and am looking to send reminders a few hours ahead of upcoming meetings.

For example, a meeting is scheduled for 2pm on June 24th, therefore by 12pm on June 24th, I'd like a reminder email sent out.

Which Automation Trigger would I need to use to do this? And what would the steps be? 

Possible solution: could I convert the time into minutes and then set up the formula such that once it hits X number of minutes before the start time, it meets "record conditions" (determined in Automations) which then leads to the automation being triggered?

Thanks in advance for your help! 

ps I'm not interested in using external tools like Make or Zapier as we're a non-profit with limited funds - they just about stretch to Airtable. 

[Alexey_Gusev]

Hi,
use formula field with IF(IS_AFTER( now(), x), 'time to notify', 'waiting'),
where x = DATEADD( meeting_time, 2 , 'hours')
In general, try to not use NOW() very often, it might affect performance. Use TODAY() when it possible.

afterwards, it's up to you .
You can set up 'When record enters view' and create view for that, according to filter on formula filter
or you can set up 'When record matches condition'.

[TheTimeSavingCo]

Yeap NOW() is probably the way to go here.  The only thing to add would be that NOW() isn't that accurate so you'll have to factor that in to your calculations.  Personally, if I want it sent by 12pm I'd probably try to set it to send by 9am just to be on the safe side I think?  From the documentation:

> This function updates when the formula is recalculated, when a base is loaded, or otherwise roughly every 15 minutes when a base is open. If the base is closed, it will update approximately every hour only when the base has time-dependent automation triggers or actions, or sync dependencies.

https://support.airtable.com/docs/formula-field-reference