---
title: window() function
description: The window() function groups records based on a time value.
aliases:
  - /v2.0/reference/flux/functions/transformations/window
menu:
  v2_0_ref:
    name: window
    parent: built-in-transformations
weight: 401
---

The `window()` function groups records based on a time value.
New columns are added to uniquely identify each window.
Those columns are added to the group key of the output tables.

A single input record will be placed into zero or more output tables, depending on the specific windowing function.

_**Function type:** Transformation_  
_**Output data type:** Object_

```js
window(
  every: 5m,
  period: 5m,
  start: 12h,
  timeColumn: "_time",
  startColumn: "_start",
  stopColumn: "_stop"
)

// OR

window(
  intervals: intervals(every: 5m, period: 5m, offset: 12h),
  timeColumn: "_time",
  startColumn: "_start",
  stopColumn: "_stop"
)
```

## Parameters

{{% note %}}
`every`,`period` or `intervals` is required.
{{% /note %}}

### every
Duration of time between windows.
Defaults to `period` value.

_**Data type:** Duration_

### period
Duration of the window.
Period is the length of each interval.
It can be negative, indicating the start and stop boundaries are reversed.
Defaults to `every` value.

_**Data type:** Duration_

### start
The start window time relative to the [`location`](/v2.0/reference/flux/language/options/#location) offset.
It can be negative, indicating that the start goes backwards in time.
The default aligns the window boundaries with `now`.

_**Data type:** Duration_

### intervals
A function that returns an interval generator, a set of intervals used as windows.

_**Data type:** Function_

###### Example interval generator function
```js
intervals(every:1d, period:8h, offset:9h)
```

{{% note %}}
When `intervals` is used, `every`, `period`, and `start` cannot be used or need to be set to 0.
{{% /note %}}

### timeColumn
The column containing time.
Defaults to `"_time"`.

_**Data type:** String_

### startColumn
The column containing the window start time.
Defaults to `"_start"`.

_**Data type:** String_

### stopColumn
The column containing the window stop time.
Defaults to `"_stop"`.

_**Data type:** String_

## Examples

#### Window data into 10 minute intervals
```js
from(bucket:"telegraf/autogen")
  |> range(start:-12h)
  |> window(every:10m)
  // ...
```

#### Window data using intervals function
The following windows data into 8 hour intervals starting at 9AM every day.
```js
from(bucket:"telegraf/autogen")
  |> range(start:-12h)
  |> window(intervals: intervals(every:1d, period:8h, offset:9h))
```

<hr style="margin-top:4rem"/>

##### Related InfluxQL functions and statements:
[GROUP BY time()](https://docs.influxdata.com/influxdb/latest/query_language/data_exploration/#the-group-by-clause)