French phrase
Merci de ~ avant ~.
Meaning
Please ___ by ___.
When to use it
A polite request to complete something by a deadline. It is somewhat formal and common in work-related writing.
Example dialogue
Merci de préparer le rapport avant vendredi.
Please prepare the report by Friday.
D'accord, je m'en occupe.
All right, I'll take care of it.