Originally Posted by
corporate-wage-slave
Apologies I did misread the question. For the Portugal requirements, it's boarding time, and yes that is a 24 hour requirement. So if boarding in (say) EWR the antigen test has to be within 24 hours of boarding at EWR, 72 hours for PCR. So your certificate needs to have a time stamp on it unless it's a same day as travel test.
Thank you. If I understand correctly, for my upcoming SFO-YYZ-LIS flight, it's the boarding time in YYZ that matters for testing purposes.