# ISO date business days count

`iso-date-business-days-count` · version 1.0.0 · Dates & times (UTC, ISO 8601) · free, no key needed

Count the business days in an inclusive date range, skipping caller-supplied weekend weekdays and holidays.

**Use when you need to: iso date business days count · count working days between dates · business days between two dates.**

## Supported

- iso date business days count
- count working days between dates
- business days between two dates

## Not supported

- built-in national holiday calendars
- timezones
- half-day rules
- signed/negative ranges

## Behavior

- start and end are strict YYYY-MM-DD calendar dates with year 0001-9999. start must not be after end.
- end minus start must not exceed 366000 days.
- weekend_days is an array of ISO weekday integers 1-7, unique, at most 6 entries. holidays is an array of unique YYYY-MM-DD dates, at most 366 entries.
- business_days counts every date d with start <= d <= end whose ISO weekday is not in weekend_days and that is not listed in holidays.

## Input

- `start` (string, required): min length 10; max length 10; pattern `^\d{4}-\d{2}-\d{2}$`
- `end` (string, required): min length 10; max length 10; pattern `^\d{4}-\d{2}-\d{2}$`
- `weekend_days` (array of integer, required): max items 6; each min 1; each max 7
- `holidays` (array of string, required): max items 366; each min length 10; each max length 10

## Output

- `business_days` (integer, required): min 0

## Limits

- year min: 1
- year max: 9999
- max range days: 366000
- max weekend days: 6
- max holidays: 366

## Example

Request input:

```json
{
  "start": "2026-09-14",
  "end": "2026-09-20",
  "weekend_days": [
    6,
    7
  ],
  "holidays": []
}
```

Response:

```json
{
  "result": {
    "business_days": 5
  }
}
```

## How to call it

### MCP

Connect `https://computefirst.net/mcp` ([setup](/docs#connect)), then call `execute` with:

```json
{
  "id": "iso-date-business-days-count",
  "version": "1.0.0",
  "input": {
    "start": "2026-09-14",
    "end": "2026-09-20",
    "weekend_days": [
      6,
      7
    ],
    "holidays": []
  }
}
```

### HTTP (no key)

```sh
curl -X POST https://computefirst.net/v1/tools/iso-date-business-days-count/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"start":"2026-09-14","end":"2026-09-20","weekend_days":[6,7],"holidays":[]}'
```

The machine-readable contract is at [/v1/tools/iso-date-business-days-count/versions/1.0.0](/v1/tools/iso-date-business-days-count/versions/1.0.0).

### CLI

```sh
node cli.mjs run iso-date-business-days-count 1.0.0 --input input.json --base-url https://computefirst.net
```

Get the client at [/clients/cli/](/clients/cli/).

## Related tools

- [ISO date age](/tools/iso-date-age): Compute the calendar-aware elapsed years, months, and days between a birth date and an as-of date.
- [ISO date business day add](/tools/iso-date-business-day-add): Add a signed count of business days to a date, skipping caller-supplied weekend weekdays and holidays.
- [ISO date difference](/tools/iso-date-difference): Whole days from start to end as a canonical integer string (end - start).
- [ISO date range intersect](/tools/iso-date-range-intersect): Compute the intersection of two inclusive [start, end] date ranges.
- [ISO date range list](/tools/iso-date-range-list): Enumerate the dates in an inclusive [start, end] range stepped by a whole number of days.
- [ISO date weekday occurrences in range](/tools/iso-date-weekday-occurrences-in-range): List every date within an inclusive date range that falls on a given ISO weekday.