January 24, 2014. Difficulty rose by +22.59% to 2.19B from 1.79B.
Change
+22.59%
New difficulty
2.19B
Period length
11.4 days
Network hashrate then (7-day)
0.0 EH/s
Bitcoin price then
$811
Hashprice then
$191,187/PH/day
The 2,016 blocks before it took 11.4 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 22.59%: 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.