Copy the following code into your ~/.screenrc
Or if you want to add the statusbar globally, add it to /etc/screenrc.

# An alternative hardstatus to display a bar at the bottom listing the
# windownames and highlighting the current windowname in blue. (This is only
# enabled if there is no hardstatus setting for your terminal)
hardstatus on
hardstatus alwayslastline
hardstatus string "%{.bW}%-w%{.rW}%n %t%{-}%+w %=%{..G} %H %{..Y} %m/%d%C%a "

When running screen, the result should look similar to this: