Claude should default to user's local timezone when reporting times, not UTC

Summary

When Claude reports times — cron schedules, log timestamps, deployment events, renewal runs, anything time-related — it defaults to UTC regardless of the user's configured timezone or locale. For users outside UTC (e.g. Europe/London, currently BST = UTC+1), this creates a consistent friction: "the renewal cron ran at 01:00" when it actually ran at 02:00 local time.

Expected behaviour

Times should be reported in the user's local timezone by default, with the offset labelled clearly (e.g. "02:00 BST" or "14:30 CET"). The local timezone should be detectable from the system (date command / TZ env var) rather than hardcoded.

Workaround

We added a rule to our team's CLAUDE.md:

Always report times in Europe/London local time (BST in summer, GMT in winter). Never report raw UTC during BST.

This works but shouldn't be necessary — it's a reasonable default for any user whose system timezone isn't UTC.

Environment

• Claude Code CLI
• System timezone: Europe/London (BST, UTC+1 at time of writing)