Overview

IsDayOff.ru is a minimalist REST API that returns whether a given date is a working day, non-working day, or short (pre-holiday) day for Russia and several CIS countries, as well as the United States. The response is a single character (0, 1, or 4), making it trivially easy to parse in any language. No authentication is required.

Beginner Tip

This is one of the most beginner-friendly APIs available: no key, no JSON parsing — just a GET request that returns a single digit. Try it in your browser by visiting https://isdayoff.ru/20250101 to see the result immediately.

Available Data

The kind of data this API exposes, based on its documentation. We could not call the endpoint to confirm the exact field names.

Non-Working Days data via REST API

Example Response

Illustrative shape only — we were not able to call this endpoint (it requires credentials or exposes no public sample URL), so the fields below show the kind of data this API returns rather than a recorded response.

JSON Response · Illustrative
{
  "input": "[email protected]",
  "is_valid": true,
  "format_valid": true,
  "details": "Input passes all validation checks"
}

Field Reference

(response body) Single character: 0 means working day, 1 means non-working day, 4 means short pre-holiday day, 100 means an error occurred

Implementation Example

Calls a real endpoint of this API. Replace any placeholder credentials with your own key.

Request
const url = "https://isdayoff.ru/";
const response = await fetch(url);
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data);

What Can You Build?

Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.

Common Errors & Troubleshooting

Generated guidance based on this API's documentation, not observed by us. Treat it as a starting point and check against the provider's own error reference.

Response is '100' (error code) The date format is wrong or the date is outside the supported range
Use YYYYMMDD format with no dashes, e.g. 20250101 instead of 2025-01-01.
Unexpected result for non-Russian dates The default country is Russia; other countries must be specified explicitly
Add the cc query parameter: ?cc=us for United States, ?cc=ua for Ukraine, etc.
Empty or unexpected response body The date string contains URL-unsafe characters or extra whitespace
Ensure the date string is plain digits in YYYYMMDD format with no spaces or punctuation.

Metadata Score Breakdown

Estimated from metadata — endpoint not independently tested

This score is estimated from observable metadata — HTTPS support, authentication model, declared CORS, and documentation reachability — because the API requires authentication or exposes no publicly testable endpoint. The five-signal breakdown is only shown for live-tested APIs.

Metadata estimate · endpoint not independently tested

Technical Specifications

Auth No Auth
HTTPS REQUIRED
CORS YES
Category Calendar
Difficulty Beginner
Listing details not endpoint-verified

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