Has anyone thought about a timeline page for Arrow and The Flash? Given the nature of Arrow to jump back and forth in time, it would seem like the perfect series for something like this. The Smallville wikia has a great timeline that not only includes dates but also the sources of the dates. For instance:

Fall 2006 - Amanda Waller hires Edward Fyers to devastate the Chinese economy. (Source: Arrow "Sacrifice")

and if a date can't be nailed down: Mid 1980's - Isabel Rochev is born. This is based Moira's statement that she was in business school when she was interning with Queen Consolidated, and Isabel telling Oliver that she's the CEO of a Fortune 500 company and under 30 years old. (Source: Arrow "Deathstroke", "Under the Hood")