Querying the current time of a city from terminal

Using a script to monitor ntpd is not commonly done. Usually a monitoring tool like nagios or munin is used to monitor the daemon. The tool can send you an alert when things go wrong. I have munin emailing me if the offset exceeds 15 milliseconds.

Normally, you should use an odd number of servers so that the daemon can perform an election among the servers if one goes off. Three is usually adequate, and more than five is excessive. Clients on your internal network should be able to get by with one internal server if you monitor it. Use legitimate servers or your ISPs NTP or DNS servers as clock sources. There are public pools as well as public servers.

ntpd is self tuning and you should not need to adjust it once it is configured and started. With recent ntpd implementations you can drop use of ntpdate entirely as they can do the initial setting of the date.

The following script will parse the offsets in the output of ntpd and report an excessive offset. You could run it from cron to email you if there are problems. The script defaults to alerting on an offset of 0.1 seconds.

#!/bin/bash
limit=100   # Set your limit in milliseconds here
offsets=$(ntpq -nc peers | tail -n +3 | cut -c 62-66 | tr -d '-')
for offset in ${offsets}; do
    if [ ${offset:-0} -ge ${limit:-100} ]; then
        echo "An NTPD offset is excessive - Please investigate"
        exit 1  
    fi  
done
# EOF

You don't say how you set the timezone, but since you set it for your own user, that has to be by setting the TZ variable. Bash (at least version 4.1.5) has some quirks when it comes to taking a TZ change into account: the change is only reflected after the shell has started an external command (it has to be an external command, forking a subshell isn't enough, nor is executing built-ins).

bash-4.1$ PS1='\t '
12:31:05 export TZ=Asia/Tokyo
12:31:12
12:31:13 echo foo
foo
12:31:14 /bin/echo foo
foo
19:31:17

So if you set TZ in your .bash_profile and you don't happen to start an external command, you will still see the time in the old timezone at the first prompt.

export TZ=GMT
# Refresh bash's idea of $TZ for prompt display purposes.
# As of bash 4.1, this requires running an external command!
if [[ $- = *i* ]]; then command true; fi