Last update
Sometimes you will come across a little type of date stamp such as:
last update: 2009-01-01
This means that the information was updated last during that date.
We tend to update most information within two weeks intervals. This reduces the load on our hardware but, most importantly, numbers rarely change much within less than four weeks (e.g., Google PageRank changes about every three months but more likely stays stable for longer).
For more information in this section see also: context, time periods, dashboard