March 24, 2013. Difficulty rose by +38.13% to 6.70M from 4.85M.
Change
+38.13%
New difficulty
6.70M
Period length
10.1 days
Network hashrate then (7-day)
—
Bitcoin price then
$64
Hashprice then
—
The 2,016 blocks before it took 10.1 days instead of 14, so the network had more hashrate than the difficulty assumed, and difficulty rose by 38.13%: 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.