Calendar API

Return calendar facts for a date in a timezone.

GET/api/v1/calendar

What It Does

Return calendar facts for a date in a timezone.

HTTP method: GET
Authentication: Public read-only; Bearer keys supported
Version: v1

Parameters

Name	Type	Required	Description
`date`	date	No	Calendar date. Example: `2026-09-09`
`timezone`	string	No	IANA timezone. Example: `Asia/Karachi`

Request Examples

cURL

curl -s 'https://worldclock.to/api/v1/calendar?date=2026-09-09&timezone=Asia/Karachi'

JavaScript

const response = await fetch("https:\/\/worldclock.to\/api\/v1\/calendar?date=2026-09-09&timezone=Asia\/Karachi");
const result = await response.json();
console.log(result.data);

PHP

$response = wp_remote_get('https://worldclock.to/api/v1/calendar?date=2026-09-09&timezone=Asia/Karachi');
 = json_decode(wp_remote_retrieve_body(), true);

Python

import requests

response = requests.get("https:\/\/worldclock.to\/api\/v1\/calendar?date=2026-09-09&timezone=Asia\/Karachi")
response.raise_for_status()
print(response.json()["data"])

Example Response

The values below illustrate the response shape. Live current-time fields are generated dynamically by the endpoint.

JSON

{
    "success": true,
    "data": {
        "date": "2026-09-09",
        "weekday": "Wednesday",
        "iso_week": 37,
        "iso_week_year": 2026,
        "day_of_year": 252,
        "days_in_month": 30,
        "leap_year": false,
        "timezone": "Asia/Karachi"
    },
    "meta": {
        "version": "v1",
        "timestamp": 1788946200
    }
}

Response Properties

Every successful response contains success: true, endpoint-specific data, and a meta object. The table below documents the public fields for this endpoint.

Property	Meaning
`success`	Boolean indicating whether the request completed successfully.
`meta.version`	Published API response version.
`meta.timestamp`	Unix timestamp for the API response instant.
`meta.timezone`	Timezone context used by the response.
`meta.rate_limit`	Per-client fair-use limit and remaining-request information on public transports.
`data.date`	Validated Gregorian date.
`data.weekday`	English weekday name.
`data.day_of_year`	Ordinal day of year.
`data.iso_week`	ISO-8601 week number.
`data.iso_week_year`	ISO week-numbering year.
`data.days_in_month`	Number of days in the month.
`data.timezone`	Timezone used to interpret the calendar date.
`data.leap_year`	Whether the Gregorian year is a leap year.

Errors use success: false with a stable machine-readable error code and a safe human-readable message.

Errors & HTTP Status Codes

400 — invalid or missing parameter.
401 — API key required or invalid when key-only access is enabled.
404 — unknown city, country or endpoint.
429 — configured rate limit reached.
503 — API disabled or maintenance mode.

Rate Limits & Caching

Current fair-use configuration is 60 requests per minute and 5000 requests per day. Cache stable directory/calculation responses where appropriate; treat current-time output as point-in-time data.