July 11, 2013. Difficulty rose by +22.63% to 26.16M from 21.34M.
Change
+22.63%
New difficulty
26.16M
Period length
11.4 days
Network hashrate then (7-day)
0.0 EH/s
Bitcoin price then
$88
Hashprice then
$1,387,950/PH/day
The 2,016 blocks before it took 11.4 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 22.63%: 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.