calendar-core

calendar-core is a skill for Claude Code from aashari/ai-agent-skills. It costs 41 tokens per session (1,362 once invoked), scanned A, original, MIT.

A technical reference for reading Apple Calendar's local macOS database, including its file location, tables and date rules. Apple Calendar is the built-in calendar application on Mac computers.

In plain words
What is it for?
Writing SQLite queries against Calendar's local database, converting its dates correctly, and finding both one-time and recurring events in a time range.
Why use it?
It prevents common mistakes such as using the wrong timestamp origin or missing future occurrences of repeating events.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: built for openclaw.

Good fit Writing SQLite queries against Calendar's local database, converting its dates correctly, and finding both one-time and recurring events in a time range.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/aashari/ai-agent-skills/calendar-core
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add aashari/ai-agent-skills --skill calendar-core
Clone the repo
git clone --depth 1 https://github.com/aashari/ai-agent-skills

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for calendar-core

README.md
[![agentmods](https://agentmods.dev/badge/skills/aashari/ai-agent-skills/calendar-core/github.svg)](https://agentmods.dev/skills/aashari/ai-agent-skills/calendar-core)
Your own site
<a href="https://agentmods.dev/skills/aashari/ai-agent-skills/calendar-core"><img src="https://agentmods.dev/badge/skills/aashari/ai-agent-skills/calendar-core/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for calendar-core

Your own site · 80×15
<a href="https://agentmods.dev/skills/aashari/ai-agent-skills/calendar-core"><img src="https://agentmods.dev/badge/skills/aashari/ai-agent-skills/calendar-core.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 41 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,362 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00041 $0.01362
Opus 5 $0.00020 $0.00681
Sonnet 5 $0.00008 $0.00272
Haiku 4.5 $0.00004 $0.00136

Measured 12d ago against content hash 624e635f9f97, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

calendar-core scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/apple-calendar/calendar-core/SKILL.md · 167 lines

How it starts

The opening of the file, as written. The whole thing — 167 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Apple Calendar — Local Data Reference

Database Location

$HOME/Library/Group Containers/group.com.apple.calendar/Calendar.sqlitedb

WAL mode — always accompanied by .sqlitedb-shm and .sqlitedb-wal. Reads work fine against the live database without locking.

DB="$HOME/Library/Group Containers/group.com.apple.calendar/Calendar.sqlitedb"
sqlite3 "$DB" "SELECT ..."

Critical: CoreData Epoch (NOT Unix Epoch)

All timestamps are seconds since January 1, 2001, not 1970. Convert in SQLite:

datetime(field + 978307200, 'unixepoch', 'localtime')

Convert current time to CoreData timestamp in bash:

NOW_CD=$(( $(date +%s) - 978307200 ))
FUTURE_CD=$(( $(date +%s) + N * 86400 - 978307200 ))

Critical: OccurrenceCache for Recurring Events

Never query CalendarItem.start_date directly for date-range queries. It only holds the original first occurrence. Future instances of recurring events only exist in OccurrenceCache.

Always use OccurrenceCache as the entry point for any time-windowed query.

occurrence_start_date is NULL for some recurring events — use COALESCE(occurrence_start_date, occurrence_date) for start time.

SQLite Schema

Key Tables

Table Key Columns
CalendarItem ROWID, summary, start_date, end_date, start_tz, end_tz, all_day, description, url, conference_url, location_id, has_attendees, has_recurrences, status, invitation_status, hidden, organizer_id, self_attendee_id, calendar_id
OccurrenceCache event_id (→CalendarItem.ROWID), occurrence_date, occurrence_start_date, occurrence_end_date
Calendar ROWID, title, color, type, store_id
Store ROWID, name (email/account name), type, disabled
Location ROWID, title, latitude, longitude, address
Participant ROWID, owner_id (→CalendarItem.ROWID), email, entity_type, role, status
Recurrence ROWID, owner_id, frequency, interval, specifier

CalendarItem.status Values

  • 0 — none / tentative
  • 1 — confirmed
  • 2 — cancelled (exclude these)

Read the full file on GitHub · 167 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 12d ago First seen · 167 lines · 41 tokens per session scan A 624e635f9f97

Subscribe to this mod's changes

calendar-core is a skill published in the GitHub repository aashari/ai-agent-skills (5 stars, last pushed 6mo ago), licensed MIT. It adds 41 tokens to every session and 1,362 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

local-ai-agents

Build local-first AI agents that run entirely on a developer workstation with Microsoft Foundry Local and Qwen function-calling models. Covers Small Language Models (SLMs), the OpenAI-compatible local endpoint, sandboxed local tools, local RAG with Chroma, local MCP servers, hybrid cloud/local routing, and the…

microsoft/ai-agents-for-beginners · 200 tokens

next-cache-components-adoption

Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…

vercel/next.js · 95 tokens

insight-error-page

Write or audit an insight-kind error page for the Next.js dev overlay. Use when creating a new errors/ .mdx page, auditing an existing one, or checking that a page matches the framework fix cards. Covers page structure, title alignment, FixCard cards with Copy prompt button, code snippets, terminology verification…

vercel/next.js · 83 tokens

next-cache-components-optimizer

Drive a Next.js route to instant navigation by setting up an agentic loop, under Cache Components / PPR, on initial load (hard navigation) and client-side navigation (soft navigation). Encode the goal as a failing @next/playwright instant() e2e and work it to green, one verified route at a time; the shipped test then…

vercel/next.js · 170 tokens

next-partial-prefetching-adoption

Turn on Partial Prefetching in a Next.js app and work through the insights it surfaces. Use when the user wants to enable or adopt Partial Prefetching, flip the partialPrefetching flag, opt routes in with export const prefetch = 'partial', audit Link prefetch={true} behavior, preserve existing prefetched UI with…

vercel/next.js · 103 tokens