wt

#! /bin/bash
set -e

# Requires WT_GOOGLE_API_KEY be set to a valid Google API Key
# That means, it needs to have both timezone API and geocoding API enabled
# https://developers.google.com/maps/documentation/timezone/get-api-key
# https://console.developers.google.com/apis/credentials

if [ "$#" -lt 1 ] || [ -z "$WT_GOOGLE_API_KEY" ]; then
    echo "Usage: $(basename $0) LOCATION" >&2
    echo ""
    echo "Will lookup the current time at LOCATION"
    echo ""
    echo "Requires environment variable WT_GOOGLE_API_KEY be set."
    echo ""
    echo "To get an API key, see https://developers.google.com/maps/documentation/timezone/get-api-key"
    echo "To ensure it has needed permissions, use https://console.developers.google.com/apis/credentials"
    echo "WT_GOOGLE_API_KEY needs to have both timezone API and geocoding API enabled"
    echo ""
  exit 1
fi

# https://gist.github.com/cdown/1163649
urlencode() {
    # urlencode <string>
    old_lc_collate=$LC_COLLATE
    LC_COLLATE=C
    
    local length="${#1}"
    for (( i = 0; i < length; i++ )); do
        local c="${1:i:1}"
        case $c in
            [a-zA-Z0-9.~_-]) printf "$c" ;;
            *) printf '%%%02X' "'$c" ;;
        esac
    done
    
    LC_COLLATE=$old_lc_collate
}

KEY=$(urlencode $WT_GOOGLE_API_KEY)
TARGET=$(urlencode "$*")
URL="https://maps.googleapis.com/maps/api/geocode/json?key=$KEY&address=$TARGET"
LATLONG=$(curl -s $URL | jq '.results[0].geometry.bounds.northeast | "\(.lat),\(.lng)"' | sed 's/\"//g')
TIMESTAMP=$(date +%s)
ZONE=$(curl -s "https://maps.googleapis.com/maps/api/timezone/json?key=$KEY&location=$LATLONG&timestamp=$TIMESTAMP" | jq .timeZoneId | sed 's/\"//g')

TZ=$ZONE date

Script to use Google Geocoding API and Timezone API to find current time at an arbitrary location (one which Google can find via Geocoding API).

Requires an API key be set as an env var, WT_GOOGLE_API_KEY but provides pointers to get it :-)