>>149027340
The ages are all loosly 15 years.
Golden Age = 1938-1956
Silver Age = 1956-1970
Bronze Age = 1970-1985

>Is there a Dark Age inserted somewhere?
Marvel considers the start of the modern age when Marvel Knights launched in 1998 so logically
Dark Age = 1985-1998

Following the usual pattern it makes sense to set the next age transition at the launch of All-New, All-Different Marvel which was in 2015 so
Modern Age = 1998-2015
LGBTPQ+ Age = 2015-*