# ISO date range contains

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

Test whether an inclusive [start, end] date range contains a given date.

**Use when you need to: iso date range contains · is date within range · point in date range check.**

## Supported

- iso date range contains
- is date within range
- point in date range check

## Not supported

- open ranges
- timezones
- range-contains-range (use iso-date-range-intersect)

## Behavior

- range is an inclusive [start, end] YYYY-MM-DD date range with year 0001-9999; start must not be after end.
- date is a strict YYYY-MM-DD calendar date.
- contains is true if range.start <= date <= range.end, false otherwise.

## Input

- `range` (object, required)
- `date` (string, required): min length 10; max length 10; pattern `^\d{4}-\d{2}-\d{2}$`

## Output

- `contains` (boolean, required)

## Limits

- year min: 1
- year max: 9999

## Example

Request input:

```json
{
  "range": {
    "start": "2026-01-01",
    "end": "2026-01-31"
  },
  "date": "2026-01-15"
}
```

Response:

```json
{
  "result": {
    "contains": true
  }
}
```

## How to call it

### MCP

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

```json
{
  "id": "iso-date-range-contains",
  "version": "1.0.0",
  "input": {
    "range": {
      "start": "2026-01-01",
      "end": "2026-01-31"
    },
    "date": "2026-01-15"
  }
}
```

### HTTP (no key)

```sh
curl -X POST https://computefirst.net/v1/tools/iso-date-range-contains/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"range":{"start":"2026-01-01","end":"2026-01-31"},"date":"2026-01-15"}'
```

The machine-readable contract is at [/v1/tools/iso-date-range-contains/versions/1.0.0](/v1/tools/iso-date-range-contains/versions/1.0.0).

### CLI

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

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

## Related tools

- [ISO date is business day](/tools/iso-date-is-business-day): Test whether a date is a business day given caller-supplied weekend weekdays and holiday dates.
- [ISO date is leap year](/tools/iso-date-is-leap-year): Test whether a proleptic Gregorian calendar year is a leap year.
- [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 range overlap](/tools/iso-date-range-overlap): Test whether two inclusive [start, end] date ranges share at least one day.
- [ISO date week count in year](/tools/iso-date-week-count-in-year): Return the number of ISO-8601 weeks (52 or 53) in an ISO week-numbering year.
- [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.