September 18, 2017. Difficulty rose by +19.58% to 1.10T from 922.72B.
Change
+19.58%
New difficulty
1.10T
Period length
11.7 days
Network hashrate then (7-day)
8.2 EH/s
Bitcoin price then
$3,679
Hashprice then
$969/PH/day
The 2,016 blocks before it took 11.7 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 19.58%: 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.