OpenWorkdays MCP

A zero-signup business-day date arithmetic API exposed as a remote MCP server. It allows AI agents to add days, count days between dates, and check if a date is a business day using a single GET request without requiring an account or API key.

Endpoint and access

No sign-in to connect and list tools. Individual tools may still need a vendor account, credentials, or permissions; check the documented prerequisites.

Community listingStreamable HTTPNo sign-inEndpoint checked 2026-11-07Published by SolvoHQ

MCP endpoint (Streamable HTTP)

https://openworkdays.vercel.app/api/mcp

Vendor documentation

What its tools do

1 tool, grouped by the hints the server advertises. Hints are self-declared, not verified behavior.

Read-only (1)

businessdays

1 of 1 have a description · 1 of 1 declare behavior hints · 1 of 1 with parameters document them all

Checks and signals

Each line is separate evidence, not a trust score.

Passed Endpoint answered the live check · Nov 7, 2026, 12:18 AM UTC
Availability 1 of 1 checks passed in 30 days

What you can do with it

Add working days to a start date
Count days between two dates
Check if a date is a business day

Source and maintenance

Community listingRegistry 0.1.0

mcp-registry: io.github.SolvoHQ/openworkdays@0.1.0 Source repository

Maintenance checked: Nov 6, 2026, 11:48 PM UTC

Protocol and capabilities

Server: openworkdays 0.1.0
MCP protocol negotiated in check: 2025-11-25
Tools: 1 advertised
Resources: Not advertised
Resource templates: Not advertised
Prompts: Not advertised

Server-advertised capabilities

{
  "tools": {}
}

Tools

1 advertised

businessdays

Advertised by the server during the last successful anonymous check.

Advertised read-only

Business-day date math. Three modes inferred from params: add (start+days -> the date N business days away, negative days = before), diff (start+end -> count of business days between, inclusive of both endpoints), is (date -> is it a business day). Optional weekend (default sat,sun) and holidays (comma list of YYYY-MM-DD you supply). No signup, no API key. Pure UTC date-only math; no time-of-day/DST/timezone.

businessdays input schema

{
  "type": "object",
  "properties": {
    "end": {
      "type": "string",
      "description": "End date YYYY-MM-DD (diff mode)"
    },
    "date": {
      "type": "string",
      "description": "Date YYYY-MM-DD to test (is mode)"
    },
    "days": {
      "type": "integer",
      "description": "Business days to add (add mode); negative subtracts"
    },
    "start": {
      "type": "string",
      "description": "Start date YYYY-MM-DD (add & diff modes)"
    },
    "weekend": {
      "type": "string",
      "description": "Comma list of weekend days, e.g. \"sat,sun\" (default sat,sun)"
    },
    "holidays": {
      "type": "string",
      "description": "Comma list of YYYY-MM-DD dates treated as non-working"
    }
  }
}

businessdays annotations

{
  "readOnlyHint": true,
  "openWorldHint": false,
  "idempotentHint": true,
  "destructiveHint": false
}

Prompts

Not advertised

No prompt definitions available.

Resources

Not advertised

No resource definitions available.

90-day uptime

A lightweight connection check about every six hours, sampled on hosts with many listings. It shows the server answered, not that its tools work.

Too few checks for a percentage yet (1 of 1 answered).

2026-11-07: 1 of 1 checks answered

30-day availability

Aggregated from read-only remote checks; this is not a tool-execution or security guarantee.

Successful checks: 1 of 1 (100%)
Average latency: 444 ms
95th percentile latency: 444 ms

Maintenance history

Public check and source-refresh events. Editorial and ownership records remain private.

Nov 7, 2026, 12:18 AM UTC · probe · passed · 444 ms · metadata changed · 1 tool(s)

Connect from your client

Each snippet registers the same endpoint; pick the client you use.

This server is operated by the named third party. Listing and endpoint checks are not an endorsement or a security audit. Review the operator's permissions, terms, and data handling before connecting. How listings are checked and corrected.

Claude Code

Run this once in a terminal. It registers the remote server. Use --scope project to write .mcp.json for the repo.

Claude Code configuration

claude mcp add --transport http openworkdays-mcp https://openworkdays.vercel.app/api/mcp

Codex

Run this once. Codex stores MCP servers in ~/.codex/config.toml (or .codex/config.toml in a trusted project).

Codex configuration

codex mcp add openworkdays-mcp --url https://openworkdays.vercel.app/api/mcp

Cursor

Merge this server into .cursor/mcp.json in your project, then enable openworkdays-mcp in your MCP settings.

Cursor configuration

{
  "mcpServers": {
    "openworkdays-mcp": {
      "url": "https://openworkdays.vercel.app/api/mcp"
    }
  }
}

Cline

Merge this into cline_mcp_settings.json (Cline → MCP Servers → Configure).

Cline configuration

{
  "mcpServers": {
    "openworkdays-mcp": {
      "type": "streamableHttp",
      "url": "https://openworkdays.vercel.app/api/mcp",
      "disabled": false
    }
  }
}

VS Code

Merge this server into .vscode/mcp.json. Use MCP: List Servers to start openworkdays-mcp and inspect its tools.

VS Code configuration

{
  "servers": {
    "openworkdays-mcp": {
      "type": "http",
      "url": "https://openworkdays.vercel.app/api/mcp"
    }
  }
}

Gemini CLI

Run this once. It writes .gemini/settings.json in the current project; pass --scope user for ~/.gemini/settings.json.

Gemini CLI configuration

gemini mcp add --transport http openworkdays-mcp https://openworkdays.vercel.app/api/mcp

Claude Desktop

Open Claude Settings > Connectors > Add custom connector, enter this server URL and enable it for the conversation. This is a manual remote-connector handoff, not a desktop JSON configuration.

Claude Desktop configuration

https://openworkdays.vercel.app/api/mcp

Windsurf

Merge this into ~/.codeium/windsurf/mcp_config.json, then refresh MCP in Cascade. Windsurf remote servers use serverUrl, not url.

Windsurf configuration

{
  "mcpServers": {
    "openworkdays-mcp": {
      "serverUrl": "https://openworkdays.vercel.app/api/mcp"
    }
  }
}

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