March 14, 2013. Difficulty rose by +10.98% to 4.85M from 4.37M.
Change
+10.98%
New difficulty
4.85M
Period length
12.6 days
Network hashrate then (7-day)
—
Bitcoin price then
$47
Hashprice then
—
The 2,016 blocks before it took 12.6 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 10.98%: 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.