December 6, 2017. Difficulty rose by +18.11% to 1.59T from 1.35T.
Change
+18.11%
New difficulty
1.59T
Period length
11.9 days
Network hashrate then (7-day)
11.7 EH/s
Bitcoin price then
$13,111
Hashprice then
$1,799/PH/day
The 2,016 blocks before it took 11.9 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 18.11%: 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.