[BUG] Scheduled triggers execute in UTC, not local timezone — not documented

Summary

Cron expressions in Claude Code scheduled triggers are evaluated in UTC, not the user's local timezone. This is not documented anywhere — the trigger creation UI/API doesn't specify a timezone, and the natural assumption is local time.

Steps to reproduce

1. Create a scheduled trigger with a cron expression for a specific local time, e.g. 0 9 * * * (intended as 9am local).
2. On a machine running UTC-5, the trigger fires at 4am local time.
3. To fire at 9am local, you must offset: 0 14 * * *.

Expected behavior

One of:

• Cron expressions use the host system's local timezone (preferred), OR
• Docs explicitly state "all cron expressions are UTC" with an offset example

Why this matters

A trigger configured to "run a morning standup at 9am" instead fires at 4am. The failure is silent — the trigger fires, just at the wrong time — so it's hard to diagnose.

Environment

• macOS Darwin 25.4.0
• Timezone: America/Bogota (UTC-5)
• Confirmed via direct testing across multiple trigger schedules