Do months need to be capitalized in Spanish?
Welcome to the forum.
In Spanish we capitalize proper names for people, places, newspapers and magazines; abbreviations of personal titles such as Dr., the equivalent of the English "Dr.," and Sr., the equivalent of "Mr."; and the first word in the titles of books, plays, movies and similar works.
Spanish does NOT capitalize:
►Calendar: Names of the days of the week and months of the year.
►Religions: Names of religions and their adherents aren't capitalized.
►Nationality: Although names of countries and cities are capitalized, words derived from them are not.
►Languages: Names of languages aren't capitalized.
Just be careful because the two languages can mix unconsciously. I've found myself not capitalizing a lot of things that should be capitalized in English because of Spanish.