For the complete documentation index, see llms.txt.

Date Calculator API

time-date 1 credits / call v2026-04-22

Add or subtract years, months, weeks, and days from a date.

Use this endpoint to add Date Calculator to your app, site, workflow, or agent without rebuilding formulas, validation, examples, and docs.

Prefer the browser version? Open the Date Calculator on miniwebtool.com.

Start free — get a key → 1,000 credits · no card · 30 seconds
What this saves

Skip a custom implementation, validation rules, examples, OpenAPI shape, billing checks, and support copy for this utility.

Where it fits

Product forms, calculator pages, finance content, education flows, support tools, automations, and agent actions.

How to evaluate

Inspect the required fields, try the hosted playground, then copy cURL, Python, or Node code into your integration.

Endpoint

POST https://api.miniwebtool.com/v1/tools/date-calculator/run

Request body

Field Type Req.
start_date str
operation
add | subtract
str
years int
months int
weeks int
days int

Cost & access

  • 1 credit per successful call.
  • Starts on: Free.
  • Max payload: 65536 bytes.
  • Privacy mode: hash_only
  • Available on: free, starter, pro, business, scale

Response envelope

{
  "request_id": "01K...",
  "tool": "date-calculator",
  "tool_version": "2026-04-22",
  "credits_used": 1,
  "result": { ... }
}

Try it

Stored only in this browser tab. Playground test key is prefilled and only works on this page. Get a live key →
add | subtract

Code examples

curl -X POST https://api.miniwebtool.com/v1/tools/date-calculator/run \
  -H 'Authorization: Bearer mwt_live_YOUR_KEY' \
  -H 'Content-Type: application/json' \
  -d '{"start_date":"2026-01-31","operation":"add","years":0,"months":1,"weeks":0,"days":7}'
import requests

resp = requests.post(
    'https://api.miniwebtool.com/v1/tools/date-calculator/run',
    headers={'Authorization': 'Bearer mwt_live_YOUR_KEY'},
    json={'start_date': '2026-01-31', 'operation': 'add', 'years': 0, 'months': 1, 'weeks': 0, 'days': 7},
)
resp.raise_for_status()
print(resp.json())
const resp = await fetch(
  'https://api.miniwebtool.com/v1/tools/date-calculator/run',
  {
    method: 'POST',
    headers: {
      'Authorization': 'Bearer mwt_live_YOUR_KEY',
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({"start_date":"2026-01-31","operation":"add","years":0,"months":1,"weeks":0,"days":7}),
  }
);
const data = await resp.json();
console.log(data);
<?php
$ch = curl_init('https://api.miniwebtool.com/v1/tools/date-calculator/run');
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'Authorization: Bearer mwt_live_YOUR_KEY',
        'Content-Type: application/json',
    ],
    CURLOPT_POSTFIELDS => json_encode([
    'start_date' => '2026-01-31',
    'operation' => 'add',
    'years' => 0,
    'months' => 1,
    'weeks' => 0,
    'days' => 7
]),
]);
$resp = curl_exec($ch);
curl_close($ch);
print_r(json_decode($resp, true));
require 'net/http'
require 'json'
require 'uri'

uri = URI('https://api.miniwebtool.com/v1/tools/date-calculator/run')
http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = (uri.scheme == 'https')

req = Net::HTTP::Post.new(uri)
req['Authorization'] = 'Bearer mwt_live_YOUR_KEY'
req['Content-Type'] = 'application/json'
req.body = {
  'start_date' => '2026-01-31',
  'operation' => 'add',
  'years' => 0,
  'months' => 1,
  'weeks' => 0,
  'days' => 7
}.to_json

resp = http.request(req)
puts JSON.parse(resp.body).inspect
package main

import (
  "bytes"
  "encoding/json"
  "fmt"
  "io"
  "net/http"
)

func main() {
  body, _ := json.Marshal(map[string]interface{}{
    "start_date": "2026-01-31",
    "operation": "add",
    "years": 0,
    "months": 1,
    "weeks": 0,
    "days": 7,
  })
  req, _ := http.NewRequest("POST", "https://api.miniwebtool.com/v1/tools/date-calculator/run", bytes.NewReader(body))
  req.Header.Set("Authorization", "Bearer mwt_live_YOUR_KEY")
  req.Header.Set("Content-Type", "application/json")

  resp, err := http.DefaultClient.Do(req)
  if err != nil { panic(err) }
  defer resp.Body.Close()
  out, _ := io.ReadAll(resp.Body)
  fmt.Println(string(out))
}
import java.net.URI;
import java.net.http.*;

var client = HttpClient.newHttpClient();
var req = HttpRequest.newBuilder()
    .uri(URI.create("https://api.miniwebtool.com/v1/tools/date-calculator/run"))
    .header("Authorization", "Bearer mwt_live_YOUR_KEY")
    .header("Content-Type", "application/json")
    .POST(HttpRequest.BodyPublishers.ofString("{\"start_date\":\"2026-01-31\",\"operation\":\"add\",\"years\":0,\"months\":1,\"weeks\":0,\"days\":7}"))
    .build();

var resp = client.send(req, HttpResponse.BodyHandlers.ofString());
System.out.println(resp.body());

How to call Date Calculator

  1. 1 Get an API key
    Get an API key. Sign up free for a bearer token. 1,000 credits/month, no card.
  2. 2 Assemble the JSON body
    Required fields: start_date, . See the Request body table below for the full schema.
  3. 3 POST to https://api.miniwebtool.com/v1/tools/date-calculator/run
    Headers: Authorization: Bearer <key> and Content-Type: application/json. Copy-paste snippets in 7 languages are under Code examples.
  4. 4 Parse the response
    Envelope: {request_id, tool, tool_version, credits_used, result}. The typed output lives in result.

Frequently asked

What does the Date Calculator API do?

Add or subtract years, months, weeks, and days from a date. Use it to add this utility without rebuilding formulas, validation, examples, and documentation.

How much does one call to Date Calculator cost?

1 credit per successful call. Failed calls (validation errors, 5xx) don't bill.

What parameters does the Date Calculator API require?

Required fields: start_date. Full schema at /v1/openapi.json.

Is the Date Calculator API deterministic?

Yes — same input, same output, forever. Tool version 2026-04-22; output shape is stable within a major version.

Can an AI agent call the Date Calculator API?

Yes. Connect to https://api.miniwebtool.com/v1/mcp over the Model Context Protocol. The agent discovers `date-calculator` with its JSON Schema automatically, so the model can plan while MiniWebtool handles the exact tool result.

What format does the API return?

JSON with a stable envelope: `{request_id, tool, tool_version, credits_used, result}`. Errors are RFC 7807 `application/problem+json`.

Use from an AI agent

Every endpoint on this site is also exposed via the Model Context Protocol at https://api.miniwebtool.com/v1/mcp. Claude, Cursor, and any MCP-capable agent can discover this tool (date-calculator) and its JSON Schema automatically — no client codegen.

# List tools the agent can call
curl -s https://api.miniwebtool.com/v1/mcp \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}' \
 | jq '.result.tools[] | select(.name=="date-calculator")'

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