# Add UK Working Days

> Adds or subtracts working days for England and Wales, Scotland or Northern Ireland, skipping weekends and the selected division's official bank holidays.

- Calculator id: `uk-add-working-days` · Category: Everyday Life (`everyday`) · Tool name: `add_uk_working_days`
- Canonical page: https://tttkmbb.com/everyday/uk-add-working-days · This document: https://tttkmbb.com/everyday/uk-add-working-days.md · JSON definition: https://tttkmbb.com/everyday/uk-add-working-days.json

## Purpose

Adds or subtracts working days for England and Wales, Scotland or Northern Ireland, skipping weekends and the selected division's official bank holidays.

**Use when:** You need a deadline a stated number of UK working days before or after a 2024-2028 date and the correct division's bank holidays matter.

**Do not use when:** You need calendar days, a local/employer/market calendar, a non-UK jurisdiction or a result outside 2024-2028.

## Example user requests

- What date is five England and Wales working days after 23 December 2026?
- Add two Scottish working days to 12 June 2026, accounting for the official bank holiday.
- Subtract ten Northern Ireland business days from 20 July 2027.


## Input

| Parameter | Type | Unit | Required | Description |
| --- | --- | --- | --- | --- |
| `start_date` | date |  | required | Starting UK civil date in YYYY-MM-DD format, within 2024-2028. |
| `working_days` | integer | working days | required | Signed working-day offset. The start date is excluded when non-zero; negative values move backward. (min -1200, max 1200) |
| `division` | enum: england-and-wales \| scotland \| northern-ireland |  | optional, default "england-and-wales" | GOV.UK bank-holiday division. England and Wales share one official list; Scotland and Northern Ireland have separate lists. |

## Output

| Field | Type | Unit | Description |
| --- | --- | --- | --- |
| `division` | string |  | Canonical GOV.UK division id. |
| `division_name` | string |  | Human-readable UK division. |
| `start_date` | date |  | Input start date. |
| `result_date` | date |  | Date reached after adding the working-day offset. |
| `result_weekday` | string |  | Weekday of result_date. |
| `result_is_working_day` | boolean |  | Whether result_date is a working day. |
| `working_days_added` | integer | working days | Signed requested offset. |
| `calendar_days_elapsed` | integer | days | Signed Gregorian difference result_date minus start_date. |
| `non_working_days_skipped` | integer | days | Weekend and bank-holiday dates crossed but not counted. |
| `bank_holidays_skipped` | list |  | Official bank-holiday dates crossed, with titles and notes. |
| `dataset_version` | string |  | Pinned Calcgrid snapshot version of the GOV.UK bank-holiday package. |
| `coverage_start` | date |  | First supported date in this pinned package. |
| `coverage_end` | date |  | Last supported date in this pinned package. |
| `source_snapshot_sha256` | string |  | SHA-256 of the complete official GOV.UK JSON response used for this package. |

## Formula

`move one calendar day at a time in sign(working_days); decrement only when the selected UK division reports is_working_day=true`

The start date is excluded for non-zero offsets. Official bank holidays and ordinary weekends are skipped. A zero offset returns the start date unchanged.

## Data Sources

- GOV.UK Bank Holidays API — https://www.gov.uk/bank-holidays.json (government, retrieved 2026-09-26)
- Open Government Licence v3.0 — https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/ (licence, retrieved 2026-09-26)

Data freshness: `static`. Pinned GOV.UK snapshot for 2024-2028; calculations fail instead of extrapolating outside coverage.

## API

- `GET https://tttkmbb.com/api/v1/calculate/uk-add-working-days?start_date=…&working_days=…`
- `POST https://tttkmbb.com/api/v1/calculate/uk-add-working-days` with JSON body `{"inputs": {…}}`
- Response: unified envelope (`success`, `request`, `result.values`, `result.units`, `sources`, `freshness`, `timestamp`, `next_actions`, `links`); see https://tttkmbb.com/docs/response-format.md
- Schema: https://tttkmbb.com/api/v1/calculators/uk-add-working-days · OpenAPI operationId `add_uk_working_days` in https://tttkmbb.com/openapi.json
- Authentication: none. Rate limit: fair use, see https://tttkmbb.com/docs/rate-limits.md.

## MCP

- Server: `https://tttkmbb.com/mcp` (Streamable HTTP, JSON-RPC 2.0, no auth)
- Tool: `add_uk_working_days` (dedicated) or `run_calculator` with `{"calculator_id": "uk-add-working-days", "inputs": {…}}`

## Example

- Christmas and New Year deadline in England and Wales: inputs `{"start_date":"2026-12-23","working_days":5,"division":"england-and-wales"}` → `{"result_date":"2027-01-04","result_weekday":"Monday","result_is_working_day":true,"working_days_added":5,"calendar_days_elapsed":12,"non_working_days_skipped":7}`
- Scottish World Cup bank holiday is skipped: inputs `{"start_date":"2026-06-12","working_days":2,"division":"scotland"}` → `{"result_date":"2026-06-17","working_days_added":2,"calendar_days_elapsed":5,"non_working_days_skipped":3}`

```
GET https://tttkmbb.com/api/v1/calculate/uk-add-working-days?start_date=2026-12-23&working_days=5&division=england-and-wales
```

## Limitations

You need calendar days, a local/employer/market calendar, a non-UK jurisdiction or a result outside 2024-2028. The start date is excluded for non-zero offsets. Official bank holidays and ordinary weekends are skipped. A zero offset returns the start date unchanged. All values are computed from the formula above; no measurement or live data is involved.

## FAQ

**Does the start date count?**

No for non-zero offsets. Plus one means the first working day after start_date; minus one means the first before it.

**Why can England and Scotland return different dates?**

Their official bank-holiday lists differ, including summer holidays and some one-off events.

## Related

- [UK Working Day Checker](https://tttkmbb.com/everyday/uk-working-day.md) — Inspect one date and its official source.
- [UK Working Days Between Dates](https://tttkmbb.com/everyday/uk-working-days-between.md) — Count working days in a UK range.
- [Add Mainland China Working Days](https://tttkmbb.com/everyday/china-add-working-days.md) — Use the mainland China official calendar with 调休.