routine vs everyday

routine is a noun but everyday is not a noun.

Word	Noun	Adjective	Verb	Adverb
routine	Yes	Yes	No	No
everyday	No	Yes	No	No

As adjectives, routine and everyday are synonyms defined as:

Other synonyms of routine include mundane, quotidian, unremarkable, workaday.

routine (noun)	everyday (noun)
an unvarying or habitual method or procedure
a set sequence of steps, part of larger computer program
a short performance that is part of a longer program

routine (adjective)	everyday (adjective)
found in the ordinary course of events	commonplace and ordinary
	appropriate for ordinary or routine occasions
	found in the ordinary course of events