In this article:
https://steemit.com/bitcoin/@bullishmoney/mainstream-media-ignorantly-spreads-bitcoin-bubble-fears

The author states the following:

Normal trading doesn't take up the entire 24-hour cycle. In fact, it only takes up 6.5 hours (Wall Street opens at 9:30am EST and closes at 4:00pm EST). Bitcoin prices, on the other hand, are broadcast throughout the entire day. Thus, after a one-year period, bitcoin and other cryptocurrency assets have traded for 8,760 hours (365 days x 24 hours).

On the flipside, Wall Street has only traded for 1,625 hours (approximately 250 business days x 6.5 hours). Thus, one year of "bitcoin time" is the equivalent of 5.4 years of "Wall Street" time (8,760 hours / 1,625 hours). In two years time, bitcoin has already experienced more than a decade's worth of trading!

The stated 2 years in my previous post was just a quick math answer, but i'm sure the exact date could be calculated with this info!