---
title: Date.FormatString
framework: foundation
role: symbol
role_heading: Structure
path: foundation/date/formatstring
---

# Date.FormatString

A type that represents a fixed date format string using string interpolation.

## Declaration

```swift
struct FormatString
```

## Overview

Overview Use Date.FormatString with Date.VerbatimFormatStyle or Date.ParseStrategy to create fixed-pattern format strings for dates. You build format strings using string interpolation with date field symbols: let format: Date.FormatString = "\(year: .defaultDigits)-\(month: .twoDigits)-\(day: .twoDigits)"

## Topics

### Default Implementations

- [ExpressibleByStringInterpolation Implementations](foundation/date/formatstring/expressiblebystringinterpolation-implementations.md)

## Relationships

### Conforms To

- [Copyable](swift/copyable.md)
- [Equatable](swift/equatable.md)
- [Escapable](swift/escapable.md)
- [ExpressibleByExtendedGraphemeClusterLiteral](swift/expressiblebyextendedgraphemeclusterliteral.md)
- [ExpressibleByStringInterpolation](swift/expressiblebystringinterpolation.md)
- [ExpressibleByStringLiteral](swift/expressiblebystringliteral.md)
- [ExpressibleByUnicodeScalarLiteral](swift/expressiblebyunicodescalarliteral.md)
- [Hashable](swift/hashable.md)
- [Sendable](swift/sendable.md)
- [SendableMetatype](swift/sendablemetatype.md)