Making a wall-clock rule timestamptz is this pack's single most common bug

Storing '9am every Tuesday' in a timestamptz column freezes it to one UTC offset at insert time -- half the year later, the rule silently means 8am instead.

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.

Buy for $993 of 3 clean-room builds passed · full refund if it fails on your machine

Is this you?

A recurrence rule's dtstart, stored as timestamptz, gets frozen to whatever UTC offset was in effect at the moment it was inserted -- Postgres has no way to know the value was meant to represent a wall-clock time that should track the zone's own future transitions, not a fixed instant. The rule silently means a different local hour the moment the zone's DST offset changes underneath it.

Why this one is easy to get wrong

timestamptz is the type every Postgres guide recommends for 'store a point in time correctly, with time zone awareness' -- which is exactly right for a booking's actual instant, and exactly wrong for an availability rule's wall-clock anchor. The two look like the same kind of data (a date and a time) right up until the next DST transition reveals they aren't.

What you get instead

dtstart_local, exdates_local, and rdates_local are all timestamp WITHOUT time zone by design -- wall clock, deliberately -- while bookings.during and blocking are tstzrange, an instant. Wall-clock columns are additionally read as TEXT via to_char(), never materialized as a JS Date, because node-postgres would otherwise interpret a bare timestamp using the Node process's own local zone, making correctness depend on the server's TZ environment variable.

Source: ARCHITECTURE.md 'Data model' — 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 →

Buy for $99 14-day refund if verify.sh fails →