October 1, 2015. Difficulty rose by +2.49% to 60.81B from 59.34B.
Change
+2.49%
New difficulty
60.81B
Period length
13.7 days
Network hashrate then (7-day)
0.4 EH/s
Bitcoin price then
$236
Hashprice then
$1,915/PH/day
The 2,016 blocks before it took 13.7 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 2.49%: an ordinary adjustment. For every machine on the network that is a pay cut of the same size until the next retarget.