JDay

API Reference

Complete reference for all JDay REST API endpoints.

Base URL

https://jday-api.jday.workers.dev

All endpoints require authentication via Authorization: Bearer <api_key>.

Endpoints

MethodPathDescription
GET/v1/is-business-dayCheck if a date is a business day
GET/v1/add-business-daysAdd or subtract business days from a date
GET/v1/count-business-daysCount business days between two dates
GET/v1/holidaysList holidays for a country and year
GET/v1/countriesList supported countries and metadata

Common Features

  • All responses include X-Request-Id header.
  • All error responses use the standard error envelope.
  • Date parameters use YYYY-MM-DD format.
  • Country codes are ISO 3166-1 alpha-2 (case-insensitive input, uppercase output).
  • Supported date range: 2025-01-01 through 2027-12-31.

OpenAPI Spec

Download the machine-readable API specification: openapi.yaml

On this page