How to get the same time and Day next month using DateTime in c#

I have a c# DateTime object and I need to increment it by one month.

example:

input           output
-------------------------------
Jan 12, 2005    Feb 12, 2005
Feb 28, 2009    Mar 28, 2009
Dec 31, 2009    Jan 31, 2010
Jan 29, 2000    Feb 29, 2000
Jan 29, 2100    Error: no Feb 29, 2100

What is the best way to do this.

My first thought (aside from some built in code) was to construct a new DateTime from pieces and handle the roll to the year myself

From stackoverflow

• Here's a complete program showing the examples given in the question. You'd probably want to use an exception in OneMonthAfter if it really shouldn't be called that way.

  using System;
  using System.Net;
  
  public class Test
  {
      static void Main(string[] args)
      {
          Check(new DateTime(2005, 1, 12));
          Check(new DateTime(2009, 2, 28));
          Check(new DateTime(2009, 12, 31));
          Check(new DateTime(2000, 1, 29));
          Check(new DateTime(2100, 1, 29));
      }
  
      static void Check(DateTime date)
      {
          DateTime? next = OneMonthAfter(date);
          Console.WriteLine("{0} {1}", date,
                            next == null ? (object) "Error" : next);
      }
  
      static DateTime? OneMonthAfter(DateTime date)
      {
          DateTime ret = date.AddMonths(1);
          if (ret.Day != date.Day)
          {
              // Or throw an exception
              return null;
          }
          return ret;
      }
  }
  

  BCS : Kevin got the fastest gun award (I accepted it before anyone even commented on it) The upshot is that his answer got me the info I need even if it wasn't totally correct.

• using System;
  
  public static class Test
  {
      public static void Main()
      {
          string[] dates = { "Jan 12, 2005", "Feb 28, 2009", "Dec 31, 2009", "Jan 29, 2000", "Jan 29, 2100" };
          foreach (string date in dates)
          {
              DateTime t1 = DateTime.Parse(date);
              DateTime t2 = t1.AddMonths(1);
              if (t1.Day != t2.Day)
                  Console.WriteLine("Error: no " + t2.ToString("MMM") + " " + t1.Day + ", " + t2.Year);
              else
                  Console.WriteLine(t2.ToString("MMM dd, yyyy"));
          }
          Console.ReadLine();   
      }
  }