---
url: >-
  https://adk.nht.io/api/@nhtio/adk/batteries/tools/datetime_math/variables/dateAddTool.md
description: Add or subtract a duration from a date/time.
---

# Variable: dateAddTool

```ts
const dateAddTool: Tool<SpooledArtifact>;
```

Defined in: [batteries/tools/datetime\_math/index.ts:39](https://github.com/NHTIO/ADK/blob/v1.20260605.0/src/batteries/tools/datetime_math/index.ts#L39)

Add or subtract a duration from a date/time.

## Remarks

All duration components (years/months/weeks/days/hours/minutes/seconds) are optional and
combined into a single Duration. Output formatting includes a time component when the input
itself has one or when any sub-day component is non-zero.