# GuidanceEstimatedArrivalMonitorDelegate

    public protocol GuidanceEstimatedArrivalMonitorDelegate : AnyObject

The protocol used to notify the delegate about changes on the estimated arrival at the destination.

- `guidanceEstimatedArrivalMonitor(_:didChangeTimeOfArrival:distance:duration:)`

  Notifies the delegate about changes on the estimated arrival to the destination.

  #### Declaration

  Swift

      func guidanceEstimatedArrivalMonitor(_ monitor: GuidanceEstimatedArrivalMonitor, didChangeTimeOfArrival timeOfArrival: Date?, distance: Measurement<UnitLength>?, duration: Measurement<UnitDuration>?)

  #### Parameters

  `monitor` | The monitor announcing the changes.
  `timeOfArrival` | The estimated time of arrival at the destination.
  `distance` | The distance to the destination.
  `duration` | The duration of the trip to the destination.