---
title: "Date"
description: "Collect a real calendar date in YYYY-MM-DD form."
group: "Build forms"
order: 15
type: "reference"
parent: "fields"
keywords:
  - "date"
  - "calendar"
  - "YYYY-MM-DD"
updated: "2026-07-14"
---

The date field collects one calendar date and stores it as a `YYYY-MM-DD` string.

## Validation

Fillo checks both the string shape and the calendar itself, so a value like `2026-02-30` is rejected. The stored answer has no time or timezone.

There's no minimum-date, maximum-date, disabled-day, or display-format option in the current schema. If you need those rules, use a custom field and validate the value in the component and your receiving system.

## Add a date field

In the dashboard, select **Add block** and choose **Date**.

```ts
const startDateField = {
  id: "start_date",
  kind: "date",
  label: "Preferred start date",
  required: true,
} as const;
```

URL prefill accepts the same `YYYY-MM-DD` value through the field ID, for example `?start_date=2026-08-01`.

## Related

- [Prefill and hidden fields](/docs/prefill): Seed a date from a query string or app state.
- [Custom](/docs/fields/custom): Add date-range rules the built-in field doesn't expose.
- [Schema and validation](/docs/schema): Keep response validation consistent across client and server.