dialog interface to set date in linux based system.

calendar.sh

#!/bin/bash
#Licensed to the Apache Software Foundation (ASF) under one
#or more contributor license agreements.  See the NOTICE file
#distributed with this work for additional information
#regarding copyright ownership.  The ASF licenses this file
#to you under the Apache License, Version 2.0 (the
#"License"); you may not use this file except in compliance
#with the License.  You may obtain a copy of the License at
#
#  http://www.apache.org/licenses/LICENSE-2.0
#
#Unless required by applicable law or agreed to in writing,
#software distributed under the License is distributed on an
#"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
#KIND, either express or implied.  See the License for the
#specific language governing permissions and limitations
#under the License.

TimeZoneOptionsByRegion () 
{
    options=$(cd /usr/share/zoneinfo/$1 && find . | sed "s|^\./||" | sed "s/^\.//" | sed '/^$/d')
}

TimeZoneRegions () 
{
    regions=$(find /usr/share/zoneinfo/. -maxdepth 1 -type d | cut -d "/" -f6 | sed '/^$/d')
}

TimeZoneSelectionMenu () 
{
    TimeZoneRegions
    regionsArray=()
    while read name; do
        regionsArray+=($name "")
    done <<< "$regions"

    region=$(dialog   --stdout \
                      --title "Timezones" \
                      --backtitle " " \
                      --ok-label "Next" \
                      --no-cancel \
                      --menu "Select a continent or ocean from the menu:" \
                      20 30 30 \
                      "${regionsArray[@]}")

    TimeZoneOptionsByRegion $region

    optionsArray=()
    while read name; do
        offset=$(TZ="$region/$name" date +%z | sed "s/00$/:00/g")
        optionsArray+=($name "($offset)")
    done <<< "$options"

    tz=$(dialog     --stdout \
                    --title "Timezones" \
                    --backtitle " " \
                    --ok-label "Next" \
                    --cancel-label "Back to Regions" \
                    --menu "Select your timezone in ${region}:" \
                    20 40 30 \
                    "${optionsArray[@]}")

    if [[ -z "${tz// }" ]]; then
        TimeZoneSelectionMenu
    else
        echo "/usr/share/zoneinfo/$region/$tz"
    fi
}

DateSelectMenu()
{
    DATE=$(date "+%d %m %Y")
    dat=$(dialog --stdout --date-format "%Y-%m-%d" --title "Calendar" --calendar "Select a date:" 0 0 $DATE)

    case $? in
        0)
            echo "$dat"   ;;
    esac
}

TimeSelectMenu()
{
    TIME=$(date "+%H %M %S")
    tim=$(dialog --stdout --title "Time" --timebox "Set the time:" 0 0 $TIME)

    case $? in
        0)
            echo "$tim"   ;;
    esac
}

if [ "$(whoami)" != 'root' ]; then
	    echo "Sorry, only the superuser can $0."
		exit 1;
fi

tZone="$(TimeZoneSelectionMenu)"
ln -fs $tZone /etc/localtime

dat="$(DateSelectMenu)"
date -s $dat

tim="$(TimeSelectMenu)"
date +%T -s "$tim"

hwclock -w

echo "$dat $tim $tZone"

TO DO
1 - Select timezone.
2 - Set date after all work.
3 - Add ASF License.
4- Add update hardware clock from system.

at the time dialog, minutes and senconds do not change