Two zone identifiers can name the same real zone and still fail ===

Asia/Calcutta resolves back as Asia/Calcutta, not its modern alias Asia/Kolkata -- modern engines no longer canonicalize aliases, so comparing two zone strings with === can wrongly call the same zone different.

This is one of the things Scheduling & Availability Core already handles. Bookings and availability that survive timezones, repeating events and daylight saving — without double-booking.

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Is this you?

Comparing two zone identifiers with === to decide whether two resources are 'in the same timezone' can return false for two zones that are, in fact, the identical real-world zone under different names -- Asia/Calcutta and Asia/Kolkata resolve to the same offsets everywhere, and modern engines deliberately no longer canonicalize one to the other, because Temporal's own standardization requires an identifier to survive round-tripping unchanged.

Why this one is easy to get wrong

Two IANA strings that name the same zone under different aliases feels like exactly the kind of thing a runtime should normalize automatically -- and for a long time, some engines did. The behavior changed as part of Temporal's standardization work, so code written or tested against an older assumption about alias canonicalization silently stops matching zones it used to consider equal.

What you get instead

The pack's own rule is stated as a hard constraint: never compare two zone identifiers with === to decide they're the same zone. Where a comparison is genuinely needed, the pack compares resolved UTC offsets at specific probe instants instead of the identifier strings themselves -- which is correct regardless of which alias either resource happens to be configured with.

Source: ARCHITECTURE.md 'Zone identity (decided)' — checkable in the pack you receive

How you actually use this

You don’t install a library or wire up an SDK. Your own coding agent builds the code in your project, and you keep it — no runtime dependency on us.

Step 1
Download and unzip
You get a folder: the docs that tell an agent what to build, a starting skeleton, and the test suite that decides when it's done.
Step 2
Open it in Claude Code or Cursor
Point your coding agent at the folder. Nothing to install, no account with us, no API key.
Step 3
Paste one prompt
The pack contains the exact prompt. Paste it as your first message and leave it alone — it works through the build itself, choosing a cheaper or stronger model per task.
Step 4
Run ./verify.sh
One command. It prints a pass or fail for every check. Green means the build is done — the same script we ran to produce the receipt on this page.

Typical build: about 22 minutes of your agent working, mostly unattended. Then you integrate the working module into your app the way you would any code you’d written yourself.

Why you can believe this

3 of 3 runs passed

We ran this pack from an empty folder 3 times and published exactly what happened — every check, the model, the token cost, the wall time. Not a testimonial, and not our opinion: the same verify.sh you run yourself. Read the full receipt →

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