# addDays

Source: https://taxilang.org/docs/language/stdlib/addDays

**Full name:** `taxi.stdlib.dates.addDays`

## Signature

```taxi
declare function <T> addDays(T, Int):T
```

## Description

Adds the specified number of days to a date, datetime, or instant. Use a negative value to subtract days.

```taxi
// Calculate an expiry date 90 days from today
find {
   @Format("yyyy-MM-dd")
   expiresOn: Date = addDays(Date, 90)
}
```

## Examples

Adds days to a date — positive to advance, negative to go back.

Query:

```taxi
given {
   start: Date = parseDate("2024-01-15")
}
find {
   @Format("yyyy-MM-dd")
   nextWeek: Date = addDays(Date, 7)
   @Format("yyyy-MM-dd")
   lastMonth: Date = addDays(Date, -30)
}
```

Result:

```json
{
  "nextWeek": "2024-01-22",
  "lastMonth": "2023-12-16"
}
```