August 22, 2015. Difficulty rose by +2.95% to 54.26B from 52.70B.
Change
+2.95%
New difficulty
54.26B
Period length
13.6 days
Network hashrate then (7-day)
0.4 EH/s
Bitcoin price then
$233
Hashprice then
$2,273/PH/day
The 2,016 blocks before it took 13.6 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 2.95%: an ordinary adjustment. For every machine on the network that is a pay cut of the same size until the next retarget.