GNOME Extensions for time/date and autologin

[Alex]

Hi all,

Does anyone know of a GNOME extension (fedora23 desktop) to control
the date/time in the top menubar thing to change it to 12-hr time
instead of 24-hr? Is an extension even necessary for that, or am I
missing some other ability to control that?

Is there an extension that enables autologin? I'd like to save my
password and have it login automatically, since it's only my desktop
with no other users.

Any other extensions you think are really useful you might recommend?

Thanks,
Alex