April 13, 2017. Difficulty rose by +4.24% to 520.81B from 499.64B.
Change
+4.24%
New difficulty
520.81B
Period length
13.4 days
Network hashrate then (7-day)
3.8 EH/s
Bitcoin price then
$1,190
Hashprice then
$551/PH/day
The 2,016 blocks before it took 13.4 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 4.24%: an ordinary adjustment. For every machine on the network that is a pay cut of the same size until the next retarget.