[Mono-dev] DateTime unspecified-to-localtime conversions different between mono and .net

[Avery Pennarun]

Hi all,

I tried the following program in Microsoft .NET 2.0 and 3.5 (same
results both times) and mono 1.2.3 and 1.2.5 (same results both
times).

I see two main differences here:

1) Dates after the Y2.038k bug in 2038 do not calculate daylight
savings time correctly.

2) DateTime.Parse in .NET seems to return a timezone-unspecified
DateTime, such that converting it ToLocalTime() or ToUniversalTime()
will always change the timestamp in one direction or the other.  In
mono, it seems to be a timezone-localtime DateTime, so that
ToLocalTime() has no effect.

Should I file a bug with this?  I've heard of people having trouble
signing up for the new bugzilla, is that fixed?

Thanks,

Avery



Source code:

 using System;

 public static class Test
 {
    public static void test(DateTime dt)
    {
	System.Console.WriteLine("{0} -- {1}",
		 dt.ToLocalTime(), dt.ToUniversalTime());
	System.Console.WriteLine("   {0} -- {1} -- {2}",
		 dt.Ticks, dt.ToLocalTime().Ticks, dt.ToUniversalTime().Ticks);
    }

    public static void Main()
    {
	test(DateTime.Parse("2007-09-27 5:14:14"));
	test(DateTime.Parse("2007-11-27 5:14:14"));
	test(DateTime.Parse("2039-09-27 5:14:14"));
	test(DateTime.Parse("2039-11-27 5:14:14"));
	test(DateTime.Parse("0001-01-01 10:01:02"));
    }
 }


Results in .NET:

9-27-2007 1:14:14 AM -- 9-27-2007 9:14:14 AM
   633264668540000000 -- 633264524540000000 -- 633264812540000000
11-27-2007 12:14:14 AM -- 11-27-2007 10:14:14 AM
   633317372540000000 -- 633317192540000000 -- 633317552540000000
9-27-2039 1:14:14 AM -- 9-27-2039 9:14:14 AM
   643363100540000000 -- 643362956540000000 -- 643363244540000000
11-27-2039 12:14:14 AM -- 11-27-2039 10:14:14 AM
   643415804540000000 -- 643415624540000000 -- 643415984540000000
1-1-0001 5:01:02 AM -- 1-1-0001 3:01:02 PM
   360620000000 -- 180620000000 -- 540620000000


Results in mono:

27/09/2007 5:14:14 AM -- 27/09/2007 9:14:14 AM
   633264668540000000 -- 633264668540000000 -- 633264812540000000
27/11/2007 5:14:14 AM -- 27/11/2007 10:14:14 AM
   633317372540000000 -- 633317372540000000 -- 633317552540000000
27/09/2039 5:14:14 AM -- 27/09/2039 10:14:14 AM
   643363100540000000 -- 643363100540000000 -- 643363280540000000
27/11/2039 5:14:14 AM -- 27/11/2039 10:14:14 AM
   643415804540000000 -- 643415804540000000 -- 643415984540000000
01/01/0001 10:01:02 AM -- 01/01/0001 3:01:02 PM
   360620000000 -- 360620000000 -- 540620000000