September 4, 2013. Difficulty rose by +32.22% to 86.93M from 65.75M.
Change
+32.22%
New difficulty
86.93M
Period length
10.6 days
Network hashrate then (7-day)
0.0 EH/s
Bitcoin price then
$129
Hashprice then
$697,423/PH/day
The 2,016 blocks before it took 10.6 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 32.22%: 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.