Script to set the time zone on *nix systems with informative feedback. Includes a one-liner for direct execution without feedback.

settimezone

#!/bin/bash

# Tested in CentOS 6.3, CentOS 6.4

# Direct one-liner:
# sudo mv /etc/localtime /etc/localtime.bak && sudo ln -s /usr/share/zoneinfo/Europe/Zurich /etc/localtime && date

S_TIMEZONE_LOCAL="/etc/localtime"
S_TIMEZONES_DIR="/usr/share/zoneinfo"
S_TIMEZONE=${1:-"Europe/Zurich"} # as in /usr/share/zoneinfo/*
S_DATE_DISPLAY_FORMAT="%A, %B %d %Y, %H:%M:%S - Timezone %z %Z"

if [ -e ${S_TIMEZONES_DIR}/${S_TIMEZONE} ]
then
  echo "Current date is: $(date +"${S_DATE_DISPLAY_FORMAT}")"
  if [ "${S_TIMEZONE_LOCAL}" -ef "${S_TIMEZONES_DIR}/${S_TIMEZONE}" ]
  then
    echo "Timezone is already set to ${S_TIMEZONE}. Nothing to do."
  else
    echo -n "Setting timezone to ${S_TIMEZONE}... "
    sudo mv ${S_TIMEZONE_LOCAL} ${S_TIMEZONE_LOCAL}.bak_$(date +"%Y%m%d%H%M%S%Z") && sudo ln -s ${S_TIMEZONES_DIR}/${S_TIMEZONE} ${S_TIMEZONE_LOCAL} && S_TIMEZONE_SET="OK"
    if [ "${S_TIMEZONE_SET}" == "OK"  ]
    then
      echo "OK"
      echo "Date is now:     $(date +"${S_DATE_DISPLAY_FORMAT}")"
    else
      echo "FAILED"
    fi
  fi
else
  echo "Timezone ${S_TIMEZONE} is not found in dir ${S_TIMEZONES_DIR}. Nothing done."
  if [ -n "$(find ${S_TIMEZONES_DIR}/ -ipath "*${S_TIMEZONE}*")" ]
  then
    echo "Did you mean one of those?"
    echo "$(find ${S_TIMEZONES_DIR}/ -ipath "*${S_TIMEZONE}*")"
  fi
fi