# getcalendarweek: Get Calendar Week (ISO Week Number)

> getcalendarweek (Get Calendar Week (ISO Week Number)) is a 1001fx API function in the group Date & time: POST https://api.1001fx.com/datetime/getcalendarweek, 1 credit per call. It works as a ready-made module in Make or as a plain HTTP call.

Returns the ISO 8601 calendar week of a date (week starts on Monday, week 1 contains the first Thursday), the week-based year, the first and last day of the week, the weekday, month and quarter.

- Group: Date & time
- Endpoint: `POST https://api.1001fx.com/datetime/getcalendarweek`
- Authentication: header `X-API-KEY: YOURSECRETAPIKEY`
- Content type: application/json
- Credits: 1 credit per call
- Ready-made in: Make
- Docs: https://1001fx.com/functions/getcalendarweek

## Parameters

- `date` (string, required) – Date: e.g. 2026-11-01 or 01.11.2026.

## Example: Get Calendar Week (ISO Week Number)

```bash
curl -X POST 'https://api.1001fx.com/datetime/getcalendarweek' \
  -H 'X-API-KEY: YOURSECRETAPIKEY' \
  -H 'Content-Type: application/json' \
  -d '{"date":"2026-11-01"}'
```