January 26, 2016. Difficulty rose by +5.89% to 120.03B from 113.35B.
Change
+5.89%
New difficulty
120.03B
Period length
13.2 days
Network hashrate then (7-day)
0.9 EH/s
Bitcoin price then
$391
Hashprice then
$1,633/PH/day
The 2,016 blocks before it took 13.2 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 5.89%: a large adjustment. For every machine on the network that is a pay cut of the same size until the next retarget.