Skip to content

Business Day Calendars

by business-days.quietworklabs.workers.dev · remote · no sign-in to list tools · v1.0.0 · published by dev.workers.quietworklabs.business-days

NYSE, Federal Reserve, TARGET2 and UK business days, holidays and T+N settlement dates.

Changes · 4
CompareRegistry entry

6 tools: 4 change things and 2 only read.

Scanned Oct 21, 2026

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

claude mcp add --transport http business-days https://business-days.quietworklabs.workers.dev/mcp

Findings

Matches of fixed checks, with the text they matched.

1 warn
  • Warnadd_business_days

    The server marks "add_business_days" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

    Matched text

    annotations: {"readOnlyHint":true,"openWorldHint":true}; The name "add_business_days" says "add": a word for a change.

    What this check looks for

Tools

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

6 tools

Changes things 4Claude Code: ask
  • add_business_daysAdds (or with negative days subtracts) N business days to a date on a joint calendar (NYSE, Fedwire/FedACH, TARGET2, UK) and lists the holidays skipped.1 finding

    Why it is in this group

    • The name "add_business_days" says "add": a word for a change.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

    Findings

    • Warn

      The server marks "add_business_days" read-only (readOnlyHint: true), and its own name, description or input give the class "write".

      Matched text

      annotations: {"readOnlyHint":true,"openWorldHint":true}; The name "add_business_days" says "add": a word for a change.

      What this check looks for
    Description, as the server wrote it
    Adds (or with negative days subtracts) N business days to a date on a joint calendar (NYSE, Fedwire/FedACH, TARGET2, UK) and lists the holidays skipped. Deterministic, no AI. Price: $0.001 USDC per call via x402 (Base); the first 5 calls per day per client are free.

    Annotations the server declares

    • readOnlyHint: true
    • openWorldHint: true
  • adjust_dateRolls a date that falls on a weekend or holiday using a business-day convention: following, modified_following, preceding, modified_preceding.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
    Rolls a date that falls on a weekend or holiday using a business-day convention: following, modified_following, preceding, modified_preceding. Typical for payment, coupon and invoice due dates. Deterministic, no AI. Price: $0.001 USDC per call via x402 (Base); the first 5 calls per day per client are free.

    Annotations the server declares

    • readOnlyHint: true
    • openWorldHint: true
  • is_business_dayWhether a date is a business day on one or more settlement calendars (NYSE, Fedwire/FedACH, TARGET2, UK), which holiday closes it, NYSE early closes, and the previous/next business…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
    Whether a date is a business day on one or more settlement calendars (NYSE, Fedwire/FedACH, TARGET2, UK), which holiday closes it, NYSE early closes, and the previous/next business day. Deterministic, no AI. Price: $0.001 USDC per call via x402 (Base); the first 5 calls per day per client are free.

    Annotations the server declares

    • readOnlyHint: true
    • openWorldHint: true
  • settlement_dateSettlement date T+N for a trade date on a joint calendar.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
    Settlement date T+N for a trade date on a joint calendar. Default XNYS,FED with t=1 (US equities since 28 May 2024). If the trade date is not a business day it is first rolled to the next one. Deterministic, no AI. Price: $0.001 USDC per call via x402 (Base); the first 5 calls per day per client are free.

    Annotations the server declares

    • readOnlyHint: true
    • openWorldHint: true
Only reads 2Claude Code: allow
  • business_days_betweenCounts business days between two dates on a joint calendar: days after start up to and including end (inclusive=true also counts start).No findings

    Why it is in this group

    • The description's first verb is "count": a word for reading.
    Description, as the server wrote it
    Counts business days between two dates on a joint calendar: days after start up to and including end (inclusive=true also counts start). Negative if end is before start. Lists weekday holidays in range. Max 10 years. Deterministic, no AI. Price: $0.001 USDC per call via x402 (Base); the first 5 calls per day per client are free.

    Annotations the server declares

    • readOnlyHint: true
    • openWorldHint: true
  • list_holidaysLists closing days for one calendar and year (2000-2099): NYSE full closures and 1 pm early closes, Federal Reserve (Fedwire/FedACH) holidays with Saturday/Sunday observance rules,…No findings

    Why it is in this group

    • The name "list_holidays" says "list": a word for reading.
    Description, as the server wrote it
    Lists closing days for one calendar and year (2000-2099): NYSE full closures and 1 pm early closes, Federal Reserve (Fedwire/FedACH) holidays with Saturday/Sunday observance rules, TARGET2 closing days, UK England & Wales bank holidays with substitute days. Weekend-only holidays with no weekday closure are omitted. Deterministic, no AI. Price: $0.001 USDC per call via x402 (Base); the first 5 calls per day per client are free.

    Annotations the server declares

    • readOnlyHint: true
    • openWorldHint: true

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 business-days https://business-days.quietworklabs.workers.dev/mcp

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": [
      "mcp__business-days__business_days_between",
      "mcp__business-days__list_holidays"
    ],
    "ask": [
      "mcp__business-days__is_business_day",
      "mcp__business-days__add_business_days",
      "mcp__business-days__settlement_date",
      "mcp__business-days__adjust_date"
    ],
    "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 business-days. Review it before you use it.