Originally Posted by eantoranz
Nevermind. We just saw that you can pass --date='1 week ago', for example... and that will do.
You can also compute dates relative to a specific date, not just today:
$ date -d "20090725 1 week ago"
Sat Jul 18 00:00:00 CEST 2009
The info page of the date command has a complete explanation of all the possible date formats.
info --index-search="Date input formats" date