A 150-Line `whentime tokyo london ny` CLI in Rust — and Why You Need IANA tzdata, Not 'UTC + N'

When you're working across time zones and someone asks "what time is it in Tokyo?", the answer should be one terminal command away: $ whentime tokyo london ny utc Here's a 150-line zero-deps Rust CLI that does exactly that, plus the gotchas you discover when you stop pretending UTC offsets are integers. 🦀 Source on GitHub : https://github.com/sen-ltd/whentime 📦 Build & run : see below Requirements Four constraints I gave myself: Friendly aliases — typing Asia/Tokyo every time loses to typi