[Bug] Timezone displayed as "Europe/Kiev" instead of "Europe/Kyiv"

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Description:
The Usage panel in Claude Code displays the timezone as Europe/Kiev, which is the deprecated IANA timezone identifier. Since tzdata 2022b, the correct identifier is Europe/Kyiv, reflecting Ukraine's official romanization adopted internationally.

Root cause (likely):
The application is either using an outdated tzdata version predating 2022b, or the legacy identifier Europe/Kiev is hardcoded somewhere in the display logic.
References:

IANA tzdata 2022b changelog: https://mm.icann.org/pipermail/tz-announce/2022-August/000073.html

What Should Happen?

Expected behavior:
Timezone is displayed as Europe/Kyiv
Actual behavior:
Timezone is displayed as Europe/Kiev
Environment:

Error Messages/Logs

Steps to Reproduce

Steps to reproduce:

Open Claude Code
Run /usage
Observe the timezone label under "Current session" and "Current week"

Expected behavior:
Timezone is displayed as Europe/Kyiv
Actual behavior:
Timezone is displayed as Europe/Kiev
Environment:

Tool: Claude Code
Timezone: Europe/Kyiv (system)

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.170

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_