As of my last update in January 2022, there isn't a widely recognized "National Max Day." However, if "Max" refers to a specific individual or character, a group of enthusiasts or fans might have designated a day to celebrate or honor them. If you're referring to someone named Max, perhaps it's a day dedicated to recognizing their contributions, achievements, or qualities.
If you have a specific context in mind for National Max Day, feel free to provide more details, and I can tailor the response accordingly!