QUICK ANSWER
"Monday" is a proper noun which is often translated as "el lunes", and "day of the week" is a noun which is often translated as "el día de la semana". Learn more about the difference between "Monday" and "day of the week" below.
Monday(
muhn
-
dey
)A proper noun refers to the name of a person, place, or thing.
day of the week(
dey
uhv
thuh
wik
)A noun is a word referring to a person, animal, place, thing, feeling, or idea (e.g., man, dog, house).
1. (general)
a. el día de la semana (M)
(m) means that a noun is masculine. Spanish nouns have a gender, which is either feminine (like la mujer or la luna) or masculine (like el hombre or el sol).
I just learned the days of the week in my Spanish class.Acabo de aprender los días de la semana en mi clase de español.