Thanks Nicholas, I think you are confirming my conclusions.
I entirely agree that only those in their left/wrong or out of their minds
would really insist on meeting a requirement for the year 9999, although I
wouldn't like to be quite so direct with the customer!... they are always
right don't you know ;-)
In reality, I am sure the customer will not expect the software to be used
in 9999. This is why I expect we will raise/declare a deficiency against the
requirements, and I can't see any reason why they would object to conceding
this deficiency.
None-the-less it would have been welcome to find someone who knew a way to
set such a date on the system clock. There is of course an alternative if
they don't concede the deficiency, and that is to represent millenia, or
years above 8907 as a member variable in some time handling wrapper class,
but then it all starts to get messy and costly to implement for no practical
reason.
To me, it still seems to me to be inconsistent that .NET declares that you
can read a DateTime representing current time, and this time structure has
the capacity to represent a year of 9999, and yet there appears to be no
converse method/function to write a value value represented in this data
structure back to the operating system.
Perhaps (if the OS can't support such a year) this is the very reason a Set
DateTime function does not exist.
I would still be interested to know if there is anything in the pipeline
(.Net 2.0?) to write a DateTime structure back to the system clock in .NET.
If not perhaps someone should consider highlighting the shortcoming in the
MSDN documentation; however irrational writing 9999 may seem.... you never
know they might invent timetravel ;-).
There also seems to be a fault in the microsoft documentation to suggest XP
can handle years to 30827 when it appears not to support this in practice (as
identified earlier in this thread).
Any further thoughts?
JAndyP (aka Japster)
"Nicholas Paldino [.NET/C# MVP]" wrote:
[color=blue]
> JAndyP,
>
> I haven't seen the original post, so I am not sure if I have this in the
> right context.
>
> However, it might be very well possible that you can not set the year
> above 8907 in the OS. I believe this is the case because the date in the OS
> is stored in a 32 bit value internally (similar to the automation format).
>
> I played around in VB, and when converting long values to dates and vice
> versa, the max values for integers created dates around that date.
>
> Of course, this is pure hypothesis.
>
> One does have to ask who in their right mind expects a software system
> to last until the year 9999? And if the requirement is that it handle
> everything up to that year, why not just go one more year, and handle that
> scenario? It just seems a little strange.
>
> --
> - Nicholas Paldino [.NET/C# MVP]
> -
mvp@spam.guard.caspershouse.com
>
> "Japster" <Japster@discussions.microsoft.com> wrote in message
> news:2763992D-2CB9-4545-BF95-51FC89DFD54E@microsoft.com...[color=green]
> >I have a slight twist to the tale....
> >
> > I am trying to implement a system which permits dates to the year 9999, to
> > meet some rather overambitious requirement!
> >
> > To avoid declaring a deficiency, I was hoping that I could use the
> > DateTime
> > structure that supports dates to end of 9999. But this seems to have been
> > thwarted by the absence of an equivalent call in .NET framework.
> >
> > Using the p/invoke solution, I have encountered a problem that if I set a
> > year above 8907 the year is not set (or perhaps reverts to existing
> > value),
> > despite SDK documentation suggesting that windows XP can handle values up
> > to
> > 30827
> > (ms-help://MS.VSCC.2003/MS.MSDNQTR.2003APR.1033/sysinfo/base/systemtime_str.htm).
> > Is this a bug? Is there a way around? Can anyone successfully set year to
> > 8908 or above?
> >
> > Finally, I am thinking that it would have been nice if the .Net framework
> > had offered an equivalent to SetSystemTime, just as it did for
> > GetSystemTime
> > (
http://msdn.microsoft.com/library/de.../win32map.asp).
> > Any idea whether this is on the cards for the future?
> >
> > Thanks in advance
> >
> > JAndyP
> >
> >
> > "Anders Norås [MCAD]" wrote:
> >[color=darkred]
> >> > How can I set the system time using a DateTime object???
> >> You can't set the local time with the DateTime structure, but you can do
> >> it
> >> with the SetSystemTime method in kernel32.dll via PInvoke. The
> >> SetSystemTime
> >> method accepts a SystemTime structure as its parameter. Populate this
> >> structure with the corresponding members of the DateTime structure.
> >>
> >> public class MyClass
> >> {
> >> public static void Main()
> >> {
> >> DateTime dt=DateTime.Now;
> >> SystemTime st=new SystemTime();
> >> st.Year=Convert.ToUInt16(dt.Year);
> >> st.Hour=Convert.ToUInt16(dt.Hour-1);
> >> SetSystemTime(ref st);
> >> }
> >>
> >> [DllImport("kernel32.dll")]
> >> public static extern int SetSystemTime(ref SystemTime systemTime);
> >> }
> >> [StructLayout(LayoutKind.Sequential)]
> >> public struct SystemTime {
> >> public System.UInt16 Year;
> >> public System.UInt16 Month;
> >> public System.UInt16 DayOfWeek;
> >> public System.UInt16 Day;
> >> public System.UInt16 Hour;
> >> public System.UInt16 Minute;
> >> public System.UInt16 Second;
> >> public System.UInt16 Millisecond;
> >> }
> >>
> >> Anders Norås
> >>
http://dotnetjunkies.com/weblog/anoras/
> >>
> >>
> >>[/color][/color]
>
>
>[/color]
