August 13, 2013. Difficulty rose by +35.88% to 50.81M from 37.39M.
Change
+35.88%
New difficulty
50.81M
Period length
10.3 days
Network hashrate then (7-day)
0.0 EH/s
Bitcoin price then
$107
Hashprice then
$997,528/PH/day
The 2,016 blocks before it took 10.3 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 35.88%: 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.