August 24, 2013. Difficulty rose by +29.40% to 65.75M from 50.81M.
Change
+29.40%
New difficulty
65.75M
Period length
10.8 days
Network hashrate then (7-day)
0.0 EH/s
Bitcoin price then
$108
Hashprice then
$763,311/PH/day
The 2,016 blocks before it took 10.8 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 29.40%: 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.