Email Trigger based on check-in time (standard or custom)

I would like to send a welcome email template shortly after a guest checks in.  Is there a trigger to initiate this email based on the account level check-in time or can I customize it based on an early check-in time? 

This is the action trigger setting I am trying for my check-in Friday:

Occurs At a scheduled time 0 days Before  has arrived at  (I am manually setting)

Thank you.

Karen

[This topic has been closed as a duplicate of another topic (Trigger Booking Field Criteria - Check In Check Out Non Standard Time)]