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io.github.physics-star-cat/databutler-calendar

by physics-star-cat · remote · no sign-in to list tools · v1.0.0 · published by GitHub user physics-star-cat

Public holidays (UK, US, DE, FR), tax-year dates and DST switches for 2026-2028.

Changes · 2
CompareRegistry entry

2 tools: 2 change things.

Scanned Oct 21, 2026

No check matched anything in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http databutler-calendar https://databutler.dev/api/mcp/calendar

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

2 tools

Changes things 2Claude Code: ask
  • calendar_factsPublic holidays, tax-year dates or daylight-saving switches for one country in 2026–2028, from the official lists and statutes.No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Public holidays, tax-year dates or daylight-saving switches for one country in 2026–2028, from the official lists and statutes. kind=holidays (uk, us, de, fr): every public holiday of the year with its date and weekday, by region — UK nations (england-and-wales, scotland, northern-ireland; substitute days flagged), US federal (statutory date plus OPM's observed date when it falls on a weekend), German Länder by code or name (nationwide = the nine bundeseinheitlichen Feiertage; partial holidays carry their scope), French metropole or alsace-moselle. kind=tax-year (uk, us, au, in, ca, de, fr, br, pl): the personal tax year's start and end with the periods for 2026–2028 and the statute or official page quoted, plus the government fiscal year where it differs. kind=dst (uk, de, fr, us, au, br): the statutory rule and the computed clocks-forward and clocks-back dates per year, with the states that observe it for Australia and observed:false for Brazil. Country names, UK nations, German Land names (Bavaria, Sachsen) and kind synonyms (bank holidays, financial year, clocks) resolve; no country lists everything covered; unknown countries, regions and years answer covered:false with the nearest matches. Entries that could not be re-verified against an official page carry nonOfficial: true.

    Annotations the server declares

    • title: Calendar facts lookup
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false
  • next_holidayThe next public holiday strictly after a date (default: today) for uk, us, de, fr, with its name, date, weekday and days until it, the three that follow, and any holiday falling on…No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    The next public holiday strictly after a date (default: today) for uk, us, de, fr, with its name, date, weekday and days until it, the three that follow, and any holiday falling on the date itself; by region as for calendar_facts (UK nations, US federal with OPM's observed date deciding the order, German Länder, French zones). The data runs to the end of 2028; a later date answers covered:false with the last date covered. From the same monthly snapshot of the official lists, with the list's URL as source.

    Annotations the server declares

    • title: Next public holiday
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 1.0.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http databutler-calendar https://databutler.dev/api/mcp/calendar

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json
{
  "permissions": {
    "allow": [],
    "ask": [
      "mcp__databutler-calendar__calendar_facts",
      "mcp__databutler-calendar__next_holiday"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as databutler-calendar. Review it before you use it.