Timezone API by Country — Full Guide 2026

Timezone data is one of those things developers underestimate until they get a bug report at 2am from a user in a different country. Here's how to handle it properly.

Why Timezone Data Matters

• Scheduling features (meeting bookings, reminders, cron jobs)
• Displaying "last updated at" timestamps in the user's local time
• Date pickers that need to know if a date is in the past for a given region
• Calculating business hours across multiple locations

Getting Timezone from a Country Code

ApogeoAPI returns a timezones array in every country response:

const res = await fetch('https://api.apogeoapi.com/v1/countries/US', {
  headers: { 'X-API-Key': 'your_key' }
});
const country = await res.json();
console.log(country.timezones);
// ['America/New_York', 'America/Chicago', 'America/Denver',
//  'America/Los_Angeles', 'America/Anchorage', 'Pacific/Honolulu']

Getting Timezone from IP (More Accurate)

For individual user sessions, IP geolocation gives you a single specific timezone — more accurate than a country-level list:

const res = await fetch('https://api.apogeoapi.com/v1/geolocate/USER_IP', {
  headers: { 'X-API-Key': 'your_key' }
});
const geo = await res.json();
console.log(geo.timezone); // 'America/Los_Angeles'

Countries with Multiple Timezones

The US has 6, Russia has 11, and Australia has 5. When your app needs to display times for a country rather than a specific user, you'll need to handle the array:

function formatTimeInCountry(date: Date, country: { timezones: string[] }) {
  // Use the first timezone as the "primary" one
  // Or let the user pick from the list
  const tz = country.timezones[0];
  return new Intl.DateTimeFormat('en-US', {
    timeZone: tz,
    dateStyle: 'medium',
    timeStyle: 'short',
  }).format(date);
}

Converting to User's Timezone in JavaScript

Once you have an IANA timezone string from the API, Intl.DateTimeFormat does the heavy lifting — no libraries needed:

const userTimezone = 'Europe/Berlin'; // from IP geo or country data

const formatter = new Intl.DateTimeFormat('en-US', {
  timeZone: userTimezone,
  year: 'numeric',
  month: 'long',
  day: 'numeric',
  hour: '2-digit',
  minute: '2-digit',
});

console.log(formatter.format(new Date())); // "April 1, 2026, 10:30 AM"

Caching Strategy

Timezone data changes very rarely (maybe once a year when a country updates DST rules). Cache aggressively:

• Country timezones: cache for 24 hours minimum, 7 days is fine
• IP-based timezone: cache per IP for 1 hour (users travel, IPs change)
• Store in Redis or localStorage depending on whether it's server-side or client-side