---
title: experimental.subDuration() function
description: >
  The `experimental.subDuration()` function subtracts a duration from a time value and
  returns a the resulting time value.
menu:
  v2_0_ref:
    name: experimental.subDuration
    parent: Experimental
weight: 201
related:
  - /v2.0/reference/flux/stdlib/experimental/addduration/
---

The `experimental.subDuration()` function subtracts a duration from a time value and
returns the resulting time value.

_**Function type:** Transformation_

{{% warn %}}
The `experimental.subDuration()` function is subject to change at any time.
By using this function, you accept the [risks of experimental functions](/v2.0/reference/flux/stdlib/experimental/#use-experimental-functions-at-your-own-risk).

This specific function will be removed once duration vectors are implemented.
See [influxdata/flux#413](https://github.com/influxdata/flux/issues/413).
{{% /warn %}}

```js
import "experimental"

experimental.subDuration(
  d: 12h,
  from: now(),
)
```

## Parameters

### d
The duration to subtract.

_**Data type:** Duration_

### from
The time to subtract the [duration](#d) from.

_**Data type:** Time_

## Examples

### Subtract six hours from a timestamp
```js
import "experimental"

experimental.subDuration(
  d: 6h,
  from: 2019-09-16T12:00:00Z,
)

// Returns 2019-09-16T06:00:00.000000000Z
```