Check out example codes for "csharp async timer". It will help you in understanding the concepts better.

Code Example 1

using System;
using System.Threading;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    sealed class Program
    {
        void run()
        {
            CancellationTokenSource cancellation = new CancellationTokenSource(
              TimeSpan.FromSeconds(8));
            Console.WriteLine("Starting action loop.");
            RepeatActionEvery(() => Console.WriteLine("Action"), 
              TimeSpan.FromSeconds(1), cancellation.Token).Wait();
            Console.WriteLine("Finished action loop.");
        }

        public static async Task RepeatActionEvery(Action action, 
          TimeSpan interval, CancellationToken cancellationToken)
        {
            while (true)
            {
                action();
                Task task = Task.Delay(interval, cancellationToken);

                try
                {
                    await task;
                }
                catch (TaskCanceledException)
                {
                    return;
                }
            }
        }

        static void Main(string[] args)
        {
            new Program().run();
        }
    }
}

Learn ReactJs, React Native from akashmittal.com