What happens if the system clock is running too fast, this is noticed, and the system clock is corrected, during a program run? I think this could break temporal monotonicity of occurrences in events, as FRP.Reactive.Internal.Clock doesn't know about system clock corrections. Am I right? If so, what, if anything, should be done about it? One rather inefficient approach would be to have a global mutable variable and a mutex for that variable, to record the last known time "reading" for the entire system, and a temporal adjustment factor (initially zero). If the difference between the last reading and the (adjusted) current reading was a positive number, that difference would be added to the temporal adjustment factor. This would prevent temporal monotonicity being broken. -- Robin