# Date.add

## Function

Returns a new Date object plus or minus the specified time.

## Syntax

```bt
date_value.add(amount, unit)
```

## Parameters

| Parameters | Type | Required | Default value | Description |
| ------ | ------ | ------ | ------ | ------ |
| amount | Number | Yes | None | Add or subtract quantities; negative numbers mean subtraction. |
| unit | String | No | seconds | Unit. |

## Return value

| Type | Description |
| ------ | ------ |
| Date | New Date object. |

## Code Example

```bt
result = date('2026-01-01 00:00:00').add(1, 'days').to_string()

// Output: 2026-01-02 00:00:00
print result
```

## Notes

- Supported units: millis, seconds, minutes, hours, days, weeks, months, years.
- The original Date object is not modified.