# Date

Explore what information is available for dates.

This type represents a local date as defined by the [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601#calendar_dates) standard.

> **Defining date values**
>
> Although dates have no literal syntax, you can use the [cast modifier](/reference/cql/expressions/modifiers/other/cast) to convert a string into a date value.

Local dates are what most people think of when they talk about dates. They do not represent a specific point in time, but rather a day in the calendar. For example, the date 2026-01-01 represents the first day of the year 2026, regardless of the time of day or daylight savings time adjustments.

## Range

The range of valid dates is from -999999999-01-01 to 999999999-12-31.

## Properties

These are the available properties:

- `day`: `integer`

  The day of the month, from 1 to 31.

- `weekday`: `string`

  The name of the day of the week, such as "monday" or "tuesday".

  The name is always in lowercase and in English.

- `month`: `integer`

  The month of the year, from 1 to 12.

- `year`: `integer`

  The year, from -999999999 to 999999999.

  This value follows the ISO 8601 standard and uses the [proleptic numbering system](https://en.wikipedia.org/wiki/Proleptic_Gregorian_calendar). Therefore, year 1 is preceded by year 0, then by year -1.