using System;

var lastActivityDate = "4/22/2020 06:00:00 AM";

            var serviceExecutionDate = "4/23/2020 05:00:00 AM";

​

            TimeSpan SLATime = new TimeSpan(48, 00, 00); // H - M - S (Might need to pull this from config)

            TimeSpan FullDayHours = new TimeSpan(23, 59, 00); // H - M - S; (This remain fixed)

​

            DateTime lastActivityDateTime;

            DateTime serviceExecutionDateTime;

​

            if (DateTime.TryParse(lastActivityDate, out lastActivityDateTime) && 

                DateTime.TryParse(serviceExecutionDate, out serviceExecutionDateTime))

            {

                DateTime dateTimeCheckerForItemsExpired = serviceExecutionDateTime.Subtract(SLATime);

                DateTime dateTimeCheckerForItemsExpiringLaterToday = dateTimeCheckerForItemsExpired.Date.Add(FullDayHours);

​

                Console.WriteLine($"{dateTimeCheckerForItemsExpired}");

                Console.WriteLine($"{dateTimeCheckerForItemsExpiringLaterToday}");

​

                if (dateTimeCheckerForItemsExpired >= lastActivityDateTime)

                    Console.WriteLine("SLA Breached...send email.");

                else if (dateTimeCheckerForItemsExpiringLaterToday >= lastActivityDateTime)

                    Console.WriteLine("SLA Will be Breached Later");

                else

                    Console.WriteLine("SLA Not Breached.");

            }