Two reasons why this is appropriate: 1) 2020 is (roughly) the year that those born in 2002 will graduate from high school. 2) As the beneficiaries of the Millennial legacy, I believe this age group will share the same values as Millennials, but be more adept at putting many of those values in practice. Already we are seeing a rapid closing of the gap between Millennials and older generations on usage of technology.
http://www.millennialmarketing.com/2010/12/what-is-a-millennial-making-sense-of-generational-labels/
The nation’s 65-and-older population grew from 44.7 million in 2013 to 46.2 million in 2014. This group, which now contains the oldest four years of the baby boom generation (born between 1946 and 1964), is 21.7 percent minority, less diverse than younger age groups.
https://www.census.gov/newsroom/press-releases/2015/cb15-113.html
1 The members of the lost generation were typically born between 1883 and 1900.  The Greatest Generation, also known as the G.I. Generation, is the generation that includes the veterans who fought in World War II. They were born from around 1900 through 1924, coming of age during the Great Depression. Journalist Tom Brokaw dubbed this the Greatest Generation in a book of the same name.
https://en.wikipedia.org/wiki/List_of_generations
Millennials Outnumber Baby Boomers and Are Far More Diverse, Census Bureau Reports. JUNE 25, 2015 — Millennials, or America’s youth born between 1982 and 2000, now number 83.1 million and represent more than one quarter of the nation’s population. Their size exceeds that of the 75.4 million baby boomers, according to new U.S. Census Bureau estimates released today.
https://www.census.gov/newsroom/press-releases/2015/cb15-113.html
It will no longer be about the technology but what you do with it. Millennials will get the credit for making a radical break in the ways their view and manage their lives, but the 20/20 generation will be the ones to actually see it through in the areas of career, the environment, social justice and more.
http://www.millennialmarketing.com/2010/12/what-is-a-millennial-making-sense-of-generational-labels/
Even more diverse than millennials are the youngest Americans: those younger than 5 years old. In 2014, this group became majority-minority for the first time, with 50.2 percent being part of a minority race or ethnic group.
https://www.census.gov/newsroom/press-releases/2015/cb15-113.html
A familial generation is a group of living beings constituting a single step in the line of descent from an ancestor. In developed nations the average familial generation length is in the high 20s and has even reached 30 years in some nations.
https://en.wikipedia.org/wiki/List_of_generations
1 As of April 2016, the Millennial generation surpassed the Boomer generation in size in the USA, with 76 million Boomers and 77 million Millennials.  Generation Z, also known as the Founders or Post-Millennials the iGeneration, or Homeland Generation, is the cohort of people born after the Millennials.
https://en.wikipedia.org/wiki/List_of_generations
Overall, millennials are more diverse than the generations that preceded them, with 44.2 percent being part of a minority race or ethnic group (that is, a group other than non-Hispanic, single-race white).
https://www.census.gov/newsroom/press-releases/2015/cb15-113.html
Term inspired by a $4 million research project and described in Don Tapscott’s book, Grown Up Digital, it refers roughly to the same age range as Millennial, those in their late teens or twenties. This term focuses on one of the defining characteristics and shapers of this generation. Personally I find it limiting.
http://www.millennialmarketing.com/2010/12/what-is-a-millennial-making-sense-of-generational-labels/
what age group is the millennial generation
The age group for millennial generation is between 1982 and 2000.