# Relationship Calculator — REST API endpoint `relationship-calculator`

Calculate how long a relationship has lasted between a start date and a target date: years/months/days, totals in days, weeks, months, hours, minutes, and seconds, the weekday it started, the next anniversary, and passed/upcoming milestones (100 days to 10 years).

- Category: datetime
- MCP server: https://mcp.findutils.com/ (Streamable HTTP, no API keys, 120 req/min per IP)
- REST endpoint: POST https://api.findutils.com/api/tools/relationship-calculator/execute (no API keys, 60 req/min per IP)
- Reference page: https://findutils.com/api/relationship-calculator/
- Same tool on the other surface: https://findutils.com/mcp/relationship-calculator/

## Call the endpoint (verified example)

```bash
curl -X POST https://api.findutils.com/api/tools/relationship-calculator/execute \
  -H "Content-Type: application/json" \
  -d '{
    "start_date": "2024-02-14",
    "target_date": "2026-04-18"
  }'

# Parameter schema
curl https://api.findutils.com/api/tools/relationship-calculator
```

## Input schema

| Argument | Type | Required | Description |
|---|---|---|---|
| `start_date` | string | yes | Relationship start date (YYYY-MM-DD). |
| `target_date` | string | no | Date to measure against (YYYY-MM-DD). Default: today (UTC). |

Example arguments (verified):

```json
{
  "start_date": "2024-02-14",
  "target_date": "2026-04-18"
}
```

OpenAPI 3.1 spec: https://findutils.com/api/openapi.json · Interactive docs: https://findutils.com/api/docs/

## Also an MCP tool

```bash
claude mcp add findutils --transport http https://mcp.findutils.com/
```

Then ask the client to call `findutils:relationship_calculator`. Full MCP reference: https://findutils.com/mcp/relationship-calculator/

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