Requests received by Serverless and Edge Functions are now enriched with headers containing information about the timezone of the visitor:

As an example, a request from Tokyo is now enriched with the following headers:

X-Vercel-IP-Latitude: 37.7749
X-Vercel-IP-Longitude: -122.4194

X-Vercel-IP-Timezone: Japan

This header is now automatically activated for all new and existing Vercel Functions for all plans — no code or configuration change needed.

Check out the documentation as well.