I prefer using GenX, GenY (for Millenials) and GenZ for the post
  2000 births. Also, I believe we may be ready for a Gen Alpha (I
  would call them AA, in the way the Excel spreadsheets go from Z
  to AA) - as there is already a significant difference that I've
  noticed between my nephew (Gen Z, age 10) and two other young
  family members (ages 2 and 3.5). GenAA is born with a Nabi /
  iphone / tablet in their hands, an unexpected significance as
  the GenZ, while familiar with tablets won't be dropping their
  pacifiers on them. It may be premature to declare a new
  generation just yet, but there is certainly something quite new
  happening.