TimeZone issue .cs

using System;

namespace ConsoleApp4
{
    class Program
    {
        private static TimeZoneInfo.TransitionTime CreateFixedDateRule(DateTime dateTime)
        {
            var time = new DateTime(dateTime.Ticks - dateTime.Date.Ticks);
            return TimeZoneInfo.TransitionTime.CreateFixedDateRule(time, dateTime.Month, dateTime.Day);
        }

        static void Main(string[] args)
        {
            var dst1Start = new DateTime(2014, 5, 16);
            var dst1End = new DateTime(2014, 6, 29);
            var dst2Start = new DateTime(2014, 7, 29);
            var dst2End = new DateTime(2014, 9, 26);

            var baseUtcOffset = new TimeSpan(2, 0, 0);
            var dstUtcOffset = new TimeSpan(3, 0, 0);
            var dstOffset = dstUtcOffset - baseUtcOffset;

            var rule1 = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(
                new DateTime(2014, 1, 1), new DateTime(2014, 6, 30), dstOffset,
                CreateFixedDateRule(dst1Start), CreateFixedDateRule(dst1End));

            var rule2 = TimeZoneInfo.AdjustmentRule.CreateAdjustmentRule(
                new DateTime(2014, 7, 1), new DateTime(2014, 12, 31), dstOffset,
                CreateFixedDateRule(dst2Start), CreateFixedDateRule(dst2End));

            var cairo = TimeZoneInfo.CreateCustomTimeZone("Africa/Cairo", baseUtcOffset, "Africa/Cairo", "EET", "EEST", new[] { rule1, rule2 });

            Console.WriteLine(cairo.GetUtcOffset(dst1End.Add(-dstOffset)));
            //MONO:  03:00:00
            //.NET and .NET Core:  02:00:00
        }
    }
}