November 17, 2013. Difficulty rose by +19.29% to 609.48M from 510.93M.
Change
+19.29%
New difficulty
609.48M
Period length
11.8 days
Network hashrate then (7-day)
0.0 EH/s
Bitcoin price then
$437
Hashprice then
$302,666/PH/day
The 2,016 blocks before it took 11.8 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 19.29%: one of the largest adjustments on record. For every machine on the network that is a pay cut of the same size until the next retarget.