# measureInterval(using:options:) Measures and emits the time interval between events received from an upstream publisher. ``` func measureInterval(using scheduler: S, options: S.SchedulerOptions? = nil) -> Publishers.MeasureInterval where S : Scheduler ``` ## Parameters `scheduler` A scheduler to use for tracking the timing of events. `options` Options that customize the delivery of elements. ## Return Value A publisher that emits elements representing the time interval between the elements it receives. ## Discussion Use [`measureInterval(using:options:)`](/documentation/Combine/Publisher/measureInterval(using:options:)) to measure the time between events delivered from an upstream publisher. In the example below, a 1-second is used as the data source for an event publisher; the [`measureInterval(using:options:)`](/documentation/Combine/Publisher/measureInterval(using:options:)) operator reports the elapsed time between the reception of events on the main run loop: ``` cancellable = Timer.publish(every: 1, on: .main, in: .default) .autoconnect() .measureInterval(using: RunLoop.main) .sink { print("\($0)", terminator: "\n") } // Prints: // Stride(magnitude: 1.0013610124588013) // Stride(magnitude: 0.9992760419845581) ``` The output type of the returned publisher is the time interval of the provided scheduler. This operator uses the provided scheduler’s [`now`](/documentation/Combine/Scheduler/now) property to measure intervals between events. --- 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)