<PackageReference Include="System.Reactive" Version="6.0.0-preview.9" />

ISchedulerPeriodic

public interface ISchedulerPeriodic
Scheduler with support for running periodic tasks. This type of scheduler can be used to run timers more efficiently instead of using recursive scheduling.
using System.Runtime.CompilerServices; namespace System.Reactive.Concurrency { [System.Runtime.CompilerServices.NullableContext(1)] public interface ISchedulerPeriodic { IDisposable SchedulePeriodic<[System.Runtime.CompilerServices.Nullable(2)] TState>(TState state, TimeSpan period, Func<TState, TState> action); } }