You should always submit items BEFORE the deadline.
And double-check if the deadline goes by postmarked date, or the date they receive it.
If the deadline for the university application is December 1st, does it mean I should submit all of the documents before Dec 1st? Or can I submit them on Dec 1st?
A 'deadline' suggests that is the day it must be received.
ON or before Dec 1st.
