Task.Delay() doesn't work with big TimeSpan (an hour), but works with smaller (10 minutes)

Question

My code is:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Timers;
using Telegram.Bot;

namespace ClassLibrary
{
    public class TimerClass
    {
        public  static async Task StartTimer(Quiz quiz)
        {
            while (StudyDay.GetNearestLesson().TotalMilliseconds > 0)
            {
                Console.WriteLine("Time from TimerClass: " +
                    StudyDay.GetNearestLesson().TotalMilliseconds);
                await Task.Delay(StudyDay.GetNearestLesson());
                quiz.Show(quiz);
            }
            Console.WriteLine("END");
        }
    }
}

StudyDay.GetNearestLesson().TotalMilliseconds gives a correct result. If time is a minute or 10 minutes, my program works, but if it's an hour, my programs doesn't work. May the reason be that my Mac goes into sleep mode, while this app is running? Please show me how to change my program^-^