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 .…