using System;

public class Program

{

    public static void Main()

    {

        DateTime dat = new DateTime(2015, 1, 29, 15,34,14); // year, month, day, hour, minutes, seconds

        var valMonths = dat.AddMonths(-1);

        var valDays = dat.AddDays(-1);

        var valHours = dat.AddMinutes(-1);

        Console.WriteLine(valHours);

        Console.WriteLine(valDays);

        Console.WriteLine(valMonths);

    }

}