Confusion over time frame

Question

There is another lesson about using the pretérito perfecto after esperar to indicate a completed action in the future. Is there any difference in sentence construction between these two cases or would intent have to be discerned entirely from context?

Inma Sánchez · Accepted Answer

Hola R
In that other lesson about the future we explain that:
"You will generally find a future reference in these sentences (unless it has been mentioned before and it is omitted.)"
One of the sentences used is:

Esperamos que hayáis encontrado lo que buscáis para entonces.
We hope you will have found what you're looking for by then.

This time marker shows that we are referring to a future event. 
I hope this clarified it.
Saludos
Inma