Free Slot Finder

Overview

You give us a window, a zone, the length of meeting you want, the intervals that are already taken and the hours you work; we return every slot that fits. We read no clock, no calendar and no holiday table, so the answer depends on nothing but what you sent and the time-zone database, whose version comes back with the result. Window, busy interval, working period and slot are all half-open, which is why two meetings that merely touch leave no gap between them.

Free-slot arithmetic looks easy until a daylight-saving day arrives, and every hand-rolled version answers it differently for the hour that does not exist.

When to use it

Scope

Non-goals

• Does not connect to any calendar service and fetches no schedule
• Does not know any public holiday; excluded dates come from you
• Does not book, hold or reserve anything it returns
• Does not expand recurring events, which time.generate_recurrence does first
• Does not count whole business days, which time.business_days_between and time.add_business_days do, nor report overlapping pairs, which time.detect_date_conflicts does

Properties

Capabilities

Cost & billing

Flat rate per invocation

File handling

How we handle your data

Input schema

Output schema

API contract

curl -sS -X POST "$BASE/v1/execute" -H "Authorization: Bearer $KEY" -H 'Content-Type: application/json' -d '{"skillKey":"productivity.calendar_availability","input":{"window":{"start":"2026-03-02T09:00:00+01:00","end":"2026-03-02T12:00:00+01:00"},"timeZone":"Europe/Brussels","durationMinutes":60}}'

import { Squillify } from "@squillify/sdk";

const sq = new Squillify({ apiKey: process.env.SQUILLIFY_API_KEY });

const { output } = await sq.execute("productivity.calendar_availability", {"window":{"start":"2026-03-02T09:00:00+01:00","end":"2026-03-02T12:00:00+01:00"},"timeZone":"Europe/Brussels","granularityMinutes":60,"durationMinutes":60});

Errors

Other limits

Limitations

• Does not connect to any calendar service and fetches no schedule
• Does not know any public holiday; excluded dates come from you
• Does not book, hold or reserve anything it returns
• Does not expand recurring events, which time.generate_recurrence does first
• Does not count whole business days, which time.business_days_between and time.add_business_days do, nor report overlapping pairs, which time.detect_date_conflicts does
• Anything needing a live calendar, since nothing here is fetched
• Whole-day business-day arithmetic, which the time skills already cover

How to call

POST /v1/execute (requires authentication)

{
  "skillKey": "productivity.calendar_availability",
  "input": {
    "window": {
      "start": "2026-03-02T09:00:00+01:00",
      "end": "2026-03-02T12:00:00+01:00"
    },
    "timeZone": "Europe/Brussels",
    "granularityMinutes": 60,
    "durationMinutes": 60
  }
}

Examples

{
  "window": {
    "start": "2026-03-02T09:00:00+01:00",
    "end": "2026-03-02T12:00:00+01:00"
  },
  "timeZone": "Europe/Brussels",
  "granularityMinutes": 60,
  "durationMinutes": 60
}

{
  "summary": {
    "slotCount": 3,
    "omittedSlotCount": 0,
    "truncated": false,
    "busyIntervalCount": 0,
    "mergedBusyCount": 0,
    "ignoredBusyCount": 0,
    "windowStart": "2026-03-02T09:00:00+01:00",
    "windowEnd": "2026-03-02T12:00:00+01:00",
    "timeZone": "Europe/Brussels",
    "durationMinutes": 60,
    "granularityMinutes": 60,
    "alignment": "WALL_CLOCK",
    "workingMinutesInWindow": 180,
    "zoneRulesVersion": "2026b"
  },
  "slots": [
    {
      "start": "2026-03-02T09:00:00+01:00",
      "end": "2026-03-02T10:00:00+01:00",
      "durationMinutes": 60
    },
    {
      "start": "2026-03-02T10:00:00+01:00",
      "end": "2026-03-02T11:00:00+01:00",
      "durationMinutes": 60
    },
    {
      "start": "2026-03-02T11:00:00+01:00",
      "end": "2026-03-02T12:00:00+01:00",
      "durationMinutes": 60
    }
  ]
}

{
  "timeZone": "Europe/Brussels",
  "window": {
    "start": "2026-03-02T09:00:00+01:00",
    "end": "2026-03-02T12:00:00+01:00"
  },
  "granularityMinutes": 60,
  "durationMinutes": 60,
  "busy": [
    {
      "end": "2026-03-02T10:30:00+01:00",
      "start": "2026-03-02T10:00:00+01:00",
      "id": "standup"
    },
    {
      "end": "2026-03-02T11:00:00+01:00",
      "start": "2026-03-02T10:30:00+01:00",
      "id": "review"
    }
  ]
}

{
  "summary": {
    "slotCount": 2,
    "omittedSlotCount": 0,
    "truncated": false,
    "busyIntervalCount": 2,
    "mergedBusyCount": 1,
    "ignoredBusyCount": 0,
    "windowStart": "2026-03-02T09:00:00+01:00",
    "windowEnd": "2026-03-02T12:00:00+01:00",
    "timeZone": "Europe/Brussels",
    "durationMinutes": 60,
    "granularityMinutes": 60,
    "alignment": "WALL_CLOCK",
    "workingMinutesInWindow": 180,
    "zoneRulesVersion": "2026b"
  },
  "slots": [
    {
      "start": "2026-03-02T09:00:00+01:00",
      "end": "2026-03-02T10:00:00+01:00",
      "durationMinutes": 60
    },
    {
      "start": "2026-03-02T11:00:00+01:00",
      "end": "2026-03-02T12:00:00+01:00",
      "durationMinutes": 60
    }
  ]
}

Recommended use cases

• Offer an agent a shortlist of times that fit a meeting length
• Check whether a window still holds a free hour once known blocks are subtracted

Avoid for

• Anything needing a live calendar, since nothing here is fetched
• Whole-day business-day arithmetic, which the time skills already cover

Related skills

Composable with

Safety & privacy

• Runs without calling any external service.
• Your payloads are never stored permanently.
• Telemetry captures metadata only — never your payload contents.
• We never train models on your payloads.
• No human reviews your payloads.

Tags