Non-Working Days API
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
Example Response
{
"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
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
Matrix Score Breakdown
Fully tested on Apr 5, 2026
Technical Specifications
Related Tags
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