English Marketing General / Conversation / Greetings / Letters grammar

Dear colleagues,

In the following phrase, where back-to-school is used as a noun, someone pointed out to me that it should be written without hyphens.

Back to school is around the corner.

I found references that prescribe the use of the hyphens when the term is being used as an adjective, as in
back-to-school sale.

https://grammargoddess.com/monday-grammar-checkup-august-10-...


That is clear to me. But I have not been able to find any unequivocal reference regarding the use of the hyphen when it comes to its use as a noun.

The author of this article, written specifically about its use a a noun, chooses to write it without the hyphen. But the article includes third-party examples where the hyphen is used, and the author does not mention anything about the use of the hyphen.

https://www.vocabulary.com/articles/dictionary/the-nouning-o...

My inclination is that it should be written with the hyphen, even when it is written as a noun, but I cannot find anything to back me up.