Well, according to "experts" (Michael Adams is counted as one) there are 4 major generations alive now
Silent Builders
Baby Boomers
Generation X
Millenial children
with each generations being about 24 years or so. I don't remember most of the exact dates (I've seen a couple talks on this and Michael Adams has written at least 3 books on the subject) but 1982 is the "birth" of the Millenial generation.
So, technically those of us born 1977-1981 are Gen X though, the amount we feel that really varies. If you look at how the Gen X were raised, I am very Gen X, which a lot of my contemporaries who came from family with better financials are more Millenial in type. It really varies.