using System;

public class Program

{

    public static void Main()

    {

        var startDate = DateTimeOffset.Parse("2022-01-02T07:01:03-08:00");

        //var startDate = DateTimeOffset.Parse("2022-01-02T17:15:23+01:00");

        var endDate = startDate.AddDays(2).Add(-startDate.TimeOfDay).AddMilliseconds(-1);

        Console.WriteLine(startDate);

        Console.WriteLine(endDate);

    }

}