If you have upgraded your Ubuntu machine to Ubuntu Saucy 13.10, one of the things that you might find missing is the date/time indicator in the menu bar. And if you visit the “System Settings -> Time and Date -> Clock” section, you might find that the option to add it to the menu bar is greyed out and disabled.
If you are having this problem, here’s the fix.
1. Reinstall indicator-datetime. It should be installed by default, but just in case you have removed it unknowingly, it is best to run the install command again.
2. Next, we are going to reconfigure the date time:
3. Lastly, restart unity.
That’s it. The date and time indicator will appear in the menu bar now.