When was a package installed?
You know the problem: "I didn't change anything"
But now, it's broken. Is there a way to see when some package was installed or a list of all packages sorted by time?
For packages that have not been installed via the Software Center but from the command line via apt-get we may view the logfile in var/log/apt/history.log.
Open the software centre and chose history tab you can see the time there.
