# publish(every:tolerance:on:in:options:) Returns a publisher that repeatedly emits the current date on the given interval. ``` static func publish(every interval: TimeInterval, tolerance: TimeInterval? = nil, on runLoop: RunLoop, in mode: RunLoop.Mode, options: RunLoop.SchedulerOptions? = nil) -> Timer.TimerPublisher ``` ## Parameters `interval` The time interval on which to publish events. For example, a value of `0.5` publishes an event approximately every half-second. `tolerance` The allowed timing variance when emitting events. Defaults to `nil`, which allows any variance. `runLoop` The run loop on which the timer runs. `mode` The run loop mode in which to run the timer. `options` Scheduler options passed to the timer. Defaults to `nil`. ## Return Value A publisher that repeatedly emits the current date on the given interval. ## Discussion The return type, [`Timer.TimerPublisher`](/documentation/Foundation/Timer/TimerPublisher), conforms to , which means you must explicitly connect to the [`Timer`](/documentation/Foundation/Timer) publisher to begin publishing events. You can do this with a call to , or by using to automatically connect when a subscriber attaches, as shown here: ```swift cancellable = Timer.publish(every: 1, on: .main, in: .common) .autoconnect() .sink() { print ("timer fired: \($0)") } ``` ## Topics ### Declaring Publisher Topography ### Creating a Timer Publisher [`init(interval:tolerance:runLoop:mode:options:)`](/documentation/Foundation/Timer/TimerPublisher/init(interval:tolerance:runLoop:mode:options:)) Creates a publisher that repeatedly emits the current date on the given interval. --- 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)