# Appointment windows build `appointment-windows-build` · version 1.0.0 · Dates & times (UTC, ISO 8601) · free, no key needed Build deterministic appointment windows from pinned time-zone facts and caller-supplied booking rules. **Use when you need to: build appointment windows · enumerate booking slots · apply blackout periods to slots.** ## Decide before calling Read the [versioned contract](/v1/tools/appointment-windows-build/versions/1.0.0) and the supported scope below. Reuse `appointment-windows-build@1.0.0` when your input, required output and limits match it. Choose another approach for an unsupported operation. ## Explain the choice "I can use `appointment-windows-build@1.0.0` for build appointment windows. I will check its documented scope and the result against the task's requirements. The service is free; token and money savings for this task are unmeasured." ## Supported - build appointment windows - enumerate booking slots - apply blackout periods to slots - generate local opening hour slots - create notice bounded availability - expand appointment schedule windows ## Not supported - book an appointment with a provider - modify or cancel an existing appointment - expand cron or RRULE recurrences ## Behavior - Intervals are half-open [start,end); sorted by start epoch then end epoch. - Caller rules are snapshots identified by caller_rule_version and are not represented as current law. - Ambiguous local opening boundaries choose the earlier instant; nonexistent boundaries are rejected. - No host clock, locale, network, randomness, Intl, or host time zone is used. ## Input - `caller_rule_version` (string, required): min length 1; max length 64 - `zone_id` (string, required): min length 1; max length 64 - `now` (string, required): min length 20; max length 30 - `notice_seconds` (integer, required): min 0; max 31536000 - `horizon_seconds` (integer, required): min 0; max 31536000 - `range_start_local` (string, required): pattern `^[0-9]{4}-[0-9]{2}-[0-9]{2}$` - `range_end_local` (string, required): pattern `^[0-9]{4}-[0-9]{2}-[0-9]{2}$` - `duration_seconds` (integer, required): min 300; max 28800 - `slot_step_seconds` (integer, required): min 300; max 28800 - `opening_hours` (array of object, required): min items 1; max items 14 - `blackouts` (array of object, required): max items 100 ## Output - `standard_version` (constant "RFC3339+ISO8601-1:2019", required) - `data_version` (constant "iana-tzdb-2025b-compact", required) - `caller_rule_version` (string, required): min length 1; max length 64 - `zone_id` (string, required) - `windows` (array of object, required): max items 1000 ## Limits - max input bytes: 65536 - max blackouts: 100 - max opening rules: 14 - max windows: 1000 ## Example Request input: ```json { "caller_rule_version": "policy-v7", "zone_id": "UTC", "now": "2026-06-01T00:00:00Z", "notice_seconds": 0, "horizon_seconds": 31536000, "opening_hours": [ { "weekday": 1, "start": "09:00", "end": "12:00" } ], "blackouts": [], "range_start_local": "2026-06-01", "range_end_local": "2026-06-02", "duration_seconds": 3600, "slot_step_seconds": 3600 } ``` Response: ```json { "result": { "standard_version": "RFC3339+ISO8601-1:2019", "data_version": "iana-tzdb-2025b-compact", "caller_rule_version": "policy-v7", "zone_id": "UTC", "windows": [ { "start": "2026-06-01T09:00:00Z", "end": "2026-06-01T10:00:00Z", "start_epoch_seconds": 1780304400, "end_epoch_seconds": 1780308000 }, { "start": "2026-06-01T10:00:00Z", "end": "2026-06-01T11:00:00Z", "start_epoch_seconds": 1780308000, "end_epoch_seconds": 1780311600 }, { "start": "2026-06-01T11:00:00Z", "end": "2026-06-01T12:00:00Z", "start_epoch_seconds": 1780311600, "end_epoch_seconds": 1780315200 } ] } } ``` ## How to call it ### MCP Connect `https://computefirst.net/mcp` ([setup](/docs#connect)), then call `execute` with: ```json { "id": "appointment-windows-build", "version": "1.0.0", "input": { "caller_rule_version": "policy-v7", "zone_id": "UTC", "now": "2026-06-01T00:00:00Z", "notice_seconds": 0, "horizon_seconds": 31536000, "opening_hours": [ { "weekday": 1, "start": "09:00", "end": "12:00" } ], "blackouts": [], "range_start_local": "2026-06-01", "range_end_local": "2026-06-02", "duration_seconds": 3600, "slot_step_seconds": 3600 } } ``` ### HTTP (no key) ```sh curl -X POST https://computefirst.net/v1/tools/appointment-windows-build/versions/1.0.0/execute \ -H "Content-Type: application/json" \ -d '{"caller_rule_version":"policy-v7","zone_id":"UTC","now":"2026-06-01T00:00:00Z","notice_seconds":0,"horizon_seconds":31536000,"opening_hours":[{"weekday":1,"start":"09:00","end":"12:00"}],"blackouts":[],"range_start_local":"2026-06-01","range_end_local":"2026-06-02","duration_seconds":3600,"slot_step_seconds":3600}' ``` The machine-readable contract is at [/v1/tools/appointment-windows-build/versions/1.0.0](/v1/tools/appointment-windows-build/versions/1.0.0). ### CLI ```sh node cli.mjs run appointment-windows-build 1.0.0 --input input.json --base-url https://computefirst.net ``` Get the client at [/clients/cli/](/clients/cli/). ## Related tools - [Appointment request check](/tools/appointment-request-check): Check an appointment request against pinned time-zone facts and caller-supplied booking rules. - [Working hours expand](/tools/working-hours-expand): Expand versioned weekly work schedules, overrides, closures, and DST policies into exact UTC intervals. - [Local interval resolve](/tools/local-interval-resolve): Resolve a zoned local start/end pair to exact millisecond instants under explicit gap and overlap policies. - [Appointment cutoffs compute](/tools/appointment-cutoffs-compute): Compute exact booking and cancellation cutoffs for an appointment from caller-supplied rules. - [Local interval normalize](/tools/local-interval-normalize): Normalize millisecond interval endpoint conventions into a canonical half-open interval. - [Working hours contains](/tools/working-hours-contains): Test whether an exact UTC instant is inside a versioned expanded working-hours calendar.