December 10, 2013. Difficulty rose by +28.41% to 908.35M from 707.41M.
Change
+28.41%
New difficulty
908.35M
Period length
10.9 days
Network hashrate then (7-day)
0.0 EH/s
Bitcoin price then
$894
Hashprice then
$508,683/PH/day
The 2,016 blocks before it took 10.9 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 28.41%: 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.