How can I display the current time & date setting?

I don't know of a single file, but this may give you the info needed:

cat /etc/timezone
grep UTC /etc/default/rcS
date
# hardware clock
sudo hwclock --show

Best example (IMHO) using timedatectl (in command-line/terminal):

$ timedatectl
      Local time: Thu 2014-07-24 19:51:23 IST
  Universal time: Thu 2014-07-24 14:21:23 UTC
        Timezone: Asia/Kolkata (IST, +0530)
     NTP enabled: no
NTP synchronized: no
 RTC in local TZ: no
      DST active: n/a

Visit the manpage for more settings and further information.

For me, date works fine:

Fri 22 Nov 2019 04:31:50 PM UTC