// For: https://stackoverflow.com/a/1004708/534812

using System;

using System.Diagnostics;

public class Program

{

    private static void Benchmark(string name, Action act, int iterations)

    {

        GC.Collect();

        act(); // run once outside of loop to avoid initialization costs

        Stopwatch sw = Stopwatch.StartNew();

        for (int i = 0; i < iterations; i++)

        {

            act();

        }

        sw.Stop();

        var microSec = 1m * sw.ElapsedTicks * 1000 * 1000 / Stopwatch.Frequency / iterations;

        Console.WriteLine(string.Format("{0}: {1:0.00} µs", name, microSec));

    }

​

    public static void Main(string[] args)

    {

        var iterations = 10000;

        for(int i = 0; i < 10; i++) {

            Benchmark("Explicit", () => { var a = VersionExplicit(); }, iterations);

            Benchmark("Modulo", () => { var b = VersionModulo(); }, iterations);

            Benchmark("DateTime.Now", () => { var c = DateTime.Now; }, iterations);

            Console.WriteLine();

        }

    }

    private static DateTime VersionExplicit() {

        var date = DateTime.Now;

        return new DateTime(date.Year, date.Month, date.Day, date.Hour, date.Minute, date.Second, date.Kind);

    }

    private static DateTime VersionModulo() {

        var dateTime = DateTime.Now;

        return dateTime.AddTicks( - (dateTime.Ticks % TimeSpan.TicksPerSecond));

    }

}