Why Web Apps Query Your Local Timezone Settings

When scheduling calendar items, displaying flight details, or syncing chat timestamps, web servers need to display times in your local timezone. Websites identify this by querying your browser's date settings. If your browser's timezone is configured incorrectly, schedules and time markers will display incorrectly. Our browser-native Timezone Checker reads your timezone properties locally, showing exactly what UTC offsets and GMT offsets your device shares. Find your timezone properties at /devicelab/device-info/timezone-checker.

Understanding Timezone Identification: IANA Codes and UTC Offsets

Timezones are identified by IANA time zone codes (e.g., `America/New_York` or `Asia/Kolkata`) and UTC/GMT offsets representing the hour difference from the prime meridian. Standard JavaScript Date APIs extract these values to ensure dates match local calendars.

How to Detect and Verify Your Timezone Locally

Navigate to /devicelab/device-info/timezone-checker. The script parses the Intl DateTimeFormat, displaying your IANA timezone name, current UTC offset, time format standard, and daylight saving status, running entirely inside your browser cache.