Get timezones for a bunch of latitudes and longitudes

getTimezonesForLocations.php

<?php
/**
 * Using Google's Google Maps Time Zone API, get the timezones for a bunch of locations which have latitudes and longitudes.
 * Output the timezones to a file.
 *
 * Note that this WILL NOT APPEND if the file already exists. It WILL OVERWRITE.
 *
 * The API returns the following output:
 *
 * {
 *  "dstOffset" : 3600,
 *  "rawOffset" : -28800,
 *  "status" : "OK",
 *  "timeZoneId" : "America/Vancouver",
 *  "timeZoneName" : "Pacific Daylight Time"
 * }
 *
 * In this gist, we are only using the timeZoneId.
 *
 * Access the API and get your key here:
 * https://console.developers.google.com/apis/api/timezone-backend.googleapis.com/overview
 *
 */

// Populate this with your list of latitudes and longitudes:
// I am using the key as an ID.
$places = [
    1 => ['lat' => 14.000000, 'lng' => -14.000000],
    2 => ['lat' => 50.000000, 'lng' => -114.000000],
    // as many as you like...
];

// Google Maps Time Zone API key:
$key = 'abc123';

// The file you want the results saved to:
$file = fopen("/somewhere/yourfile.txt", "w");

// If we want to rate limit by count:
// 0 for unlimited. The Google enforced hard limit for a free account is 2500.
$limit = 0;

// Just keeping track of how many we've processed:
$count = 0;

// If we want to rate limit by time:
$timeBetweenCurls = 0;

$curl = curl_init();

foreach ($places as $id => $place) {

    $url = "https://maps.googleapis.com/maps/api/timezone/json?location=" . $place['lat'] . "," . $place['lng'] . "&timestamp=" . time() . "&key=" . $key;

    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);

    $response = json_decode(curl_exec($curl), true);

    // Customize this to whatever format you want:
    $output = "\nTimezone is " . $response['timeZoneId'] . " for " . $id . ".";

    // If we want to see the results as we're getting them:
    // print($output);

    fwrite($file, $output);

    $count++;
    if ($limit > 0 && $count >= $limit) {
        break;
    } else {
        sleep($timeBetweenCurls);
    }
}

curl_close($curl);

fclose($file);