This post is not intended for those who can adjust their screen brightness via GUI without much difficulties. I mention this command line option considering a lot of complaints from users controlling the brightness through GUI. Disregard this if you are comfortable with controlling brightness via GUI. If your hardware drivers(especially regarding screen) are free from errors, then you can adjust your screen brightness with the help of xbacklight utility. xbacklight may not be installed by default. So you must download and install the utility. Don’t worry, it is of negligible size(may be less than 1 MB).
After installing run the following command
Don’t think this customization option in a complex manner. Just as I explained in the previous post, title-mentioned options are easily available for everyone through the gnome-shell extension domain. The only thing you need to do is to enable the same from their domain. Here is the link. Enable it by sliding the ON-OFF bar on the left side. Now the default status menu will be changed to look somewhat similar to one displayed above.
Note:- Depending upon the no.of users in you GNU/Linux system Switch User option may be present or not. It will be available with more than one user. Alternate method to do the same via terminal is to install the gnome-shell-extenions and then enable the required extension. Steps are as follows..
By default installation of Gnome desktop environment in GNU/Linux systems does not show the complete date and time in the gnome-panel. You can choose either of the following two options for displaying the date and time in the panel.
 Access the gnome-shell extensions site from here. Install Full clock extension. I cannot assure you full guarantee by doing this. Because when I tried, it was a failure, don’t know what happened. You can try this but I like to do via the second method.
 Open up the terminal and type the following
user@GNULinux:~$gsettings set org.gnome.shell.clock show-date true
Now date and time will be displayed in a beautiful manner. I prefer this, because it is far better than the first one since it doesn’t require any complex procedures.