# appendInterpolation(timerInterval:pauseTime:countsDown:showsHours:) Appends a timer interval to a string interpolation. ``` mutating func appendInterpolation(timerInterval: ClosedRange, pauseTime: Date? = nil, countsDown: Bool = true, showsHours: Bool = true) ``` ## Parameters `timerInterval` The interval between where to run the timer. `pauseTime` If present, the date at which to pause the timer. The default is `nil` which indicates to never pause. `countsDown` Whether to count up or down. The default is `true`. `showsHours` Whether to include an hours component if there are more than 60 minutes left on the timer. The default is `true`. ## Discussion Don’t call this method directly; it’s used by the compiler when interpreting string interpolations. --- 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)