The generation changes is a recent example of a flip-flop.
1927 - 1951: Generation = anointed
1951 to 1995: Generation = those born before 1914 (a limited time frame)
1995 - 2008: Generation = wicked men who don't accept the sign (no time frame on when the generation will end)
2008 - 2010: Generation = anointed (again open ended as to when the generation will end)
2010 - current: Generation = anointed from 1914 that overlap with another group that live during the first groups lifetime (back to a limited time frame for the generation)