JDay

Supported Date Range

The date range supported by JDay v1 and how boundary conditions work.

v1 Date Range

JDay v1 supports dates from 2025-01-01 through 2027-12-31 inclusive.

Per-Endpoint Rules

EndpointRule
is-business-dayThe queried date must be in range.
add-business-daysBoth the input date and the computed end_date must be in range.
count-business-daysBoth start and end must be in range.
holidaysyear must be one of 2025, 2026, or 2027.

Out-of-Range Behavior

For date-bearing endpoints, requests outside the supported range return:

{
  "error": {
    "code": "date_out_of_range",
    "message": "Date must be between 2025-01-01 and 2027-12-31 inclusive."
  },
  "request_id": "018f7d1a-3a51-7f4b-9c78-830f8b6ce220"
}

For GET /v1/holidays, malformed or unsupported year values return 400 invalid_year (not date_out_of_range).

Boundary Behavior

The is-business-day endpoint includes next_business_day and previous_business_day fields. At the edges of the supported range, the field that would fall outside the range is returned as null:

{
  "date": "2027-12-31",
  "next_business_day": null,
  "previous_business_day": "2027-12-30"
}

For add-business-days, if a valid in-range start date would produce an end_date outside the supported range, the API returns 400 date_out_of_range before performing any expensive traversal.

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