1997–2012 is the definition used by Pew (which also uses the oft-quoted 1981–1996 definition for millennials). Statistics Canada uses 2012 too, while the US census uses 2013.

But anyway, the earliest cutoff I could find was 2010, which is what the Australian Bureau of Statistics uses, and my point still works for 2010 kids. (The ABS's other boundaries also don't change the fact that I'm young millennial but my sister old gen Z, or that my parents are young boomers, either. So every point I was making still works.)