# list_periods

> Which dates make up each period

**Call:** `GET /v1/periods`  
**Price:** Free  
**Available:** soft launch  
**Contract:** https://api.gwix.ai/docs/reference

## What it's for

Period labels and their exact start and end dates, and the last complete week. Free.

## Use it when

- Converting "last quarter" or "2026-Q3" into exact dates for a user.

## Inputs

| Name | In | Type | Required | Meaning |
|---|---|---|---|---|
| `type` | query | string: week | month | quarter | year | yes |  |
| `from` | query | string |  |  |
| `to` | query | string |  |  |

## What comes back

`last_complete_week`, `data_release`, `periods`.

## Rules

**Periods.** Periods are whole Monday-Sunday weeks. A month is 4 weeks, a quarter 13, a year 52, anchored to complete weeks ending on or before the period's last day. There are no partial periods; the current week is never included until it is complete. Ask for periods with `interval` plus `start_period` and `end_period` labels (custom date ranges are not available at launch).

## When it doesn't work

| Status | What to do |
|---|---|
| 400 | Fix the request; `invalid_params` names each bad parameter. |
| 429 | Rate or concurrency limit. Wait `Retry-After` seconds. |

## Example response

```json
{
  "last_complete_week": "2026-10-25",
  "periods": [
    {
      "label": "2025-01",
      "type": "month",
      "start": "2024-12-30",
      "end": "2025-01-26"
    },
    {
      "label": "2025-Q2",
      "type": "quarter",
      "start": "2025-03-31",
      "end": "2025-06-29"
    }
  ]
}
```