# SystemFormatStyle.DateOffset A format style that displays the time offset between a comparison date and an anchor date that you provide. ``` struct DateOffset ``` ## Overview `DateOffset` formats the difference between the input date and the specified anchor into a human-readable string. It automatically chooses between a compact time representation (like `5:32`) and a units representation (like `2 days, 3 hours`) based on what values you set in `allowedFields`. When you use this with [`Text`](/documentation/SwiftUI/Text), the value the style displays updates automatically as time progresses: ```swift let startDate = Date.now // Shows elapsed time since startDate. Text(.currentDate, format: .offset(to: startDate)) // Output: "3 minutes, 42 seconds" ``` ### Controlling which units appear By default, the style may show year, month, day, hour, minute, and second fields. You can restrict this with `allowedFields`: ```swift // Only show hours, minutes, and seconds in time format. Text(.currentDate, format: .offset( to: startDate, allowedFields: [.hour, .minute, .second], maxFieldCount: 3)) // Output: "1:23:45" ``` When you limit the allowed fields to `[.minute, .second]` (with `maxFieldCount: 2`) or `[.hour, .minute, .second]` (with `maxFieldCount: 3`), the style uses a time-pattern format: |Allowed fields |Max fields|Example output | |----------------------------|----------|-------------------| |`[.minute, .second]` |2 |`5:32` | |`[.hour, .minute, .second]` |3 |`1:05:32` | |`[.hour, .minute]` |2 |`1 hour, 5 minutes`| |`[.year, .month, .day, ...]`|2 |`2 days, 3 hours` | ### Controlling the sign The `sign` parameter determines how the style indicates whether the offset is in the past or future: ```swift // .automatic (default): sign only when date is before anchor Text(.currentDate, format: .offset(to: anchor)) // 5 seconds after anchor: "5 seconds" // 5 seconds before anchor: "−5 seconds" // .never: no sign regardless of direction Text(.currentDate, format: .offset(to: anchor, sign: .never)) // 5 seconds before anchor: "5 seconds" // .always(includingZero: false): sign for both directions Text(.currentDate, format: .offset(to: anchor, sign: .always(includingZero: false))) // 5 seconds after anchor: "+5 seconds" // 5 seconds before anchor: "−5 seconds" // 0 seconds from anchor: "0 seconds" ``` ### Limiting the number of fields The `maxFieldCount` parameter controls how many units appear in the output. For an offset of 1 hour, 34 minutes, and 23 seconds from the anchor: |`maxFieldCount`|Output | |---------------|--------------------------------| |2 (default) |`1 hour, 34 minutes` | |1 |`1 hour` | |3 |`1 hour, 34 minutes, 23 seconds`| ## Relationships ### Conforms To [`Escapable`](/documentation/Swift/Escapable) [`Equatable`](/documentation/Swift/Equatable) [`SendableMetatype`](/documentation/Swift/SendableMetatype) [`Encodable`](/documentation/Swift/Encodable) [`FormatStyle`](/documentation/Foundation/FormatStyle) [`Sendable`](/documentation/Swift/Sendable) [`Decodable`](/documentation/Swift/Decodable) [`Copyable`](/documentation/Swift/Copyable) [`DiscreteFormatStyle`](/documentation/Foundation/DiscreteFormatStyle) [`Hashable`](/documentation/Swift/Hashable) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)