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SystemTimeToDateTime

Posted on 2002-05-07
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Last Modified: 2012-06-21
It's 4:20 in the morning, and this is really annoying me.  Calling this function produces a debugger exception notification with the following error message:

"Invalid argument to date encode."

The problem line is the call to SystemTimeToDateTime, though I don't see why.  TZSystem.StandardDate is a _SYSTEMTIME, and SystemTimeToDateTime wants a _SYSTEMTIME, so what's the problem?

procedure ProcedureName;
var
  TZSystem: TTimeZoneInformation;
  DateTime: TDateTime;
begin
  GetTimeZoneInformation(TZSystem);

  DateTime := SystemTimeToDateTime(TZSystem.StandardDate);
end;

Brian
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Question by:Traal
1 Comment
 
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TOndrej earned 50 total points
ID: 6993502
Read the documentation of GetTimeZoneIformation.
StandardDate is not really a valid _SYSTEMTIME. It's purpose is to specify when the transition from daylight saving time to standard time occurs, using a special notation.
First of all, it may not even be specified, in which case wMonth = 0.
If it is specified, then wYear = 0, wDayOfWeek contains the day of week, wDay contains a value in the range 1 - 5 (1 meaning the first wDayOfWeek, 5 meaning the last).
For example:
wYear = 0, wMonth = 4, wDayOfWeek = 0, wDay = 1
would mean "first Sunday in April".

The other members of the structure are IMHO undefined and not used.

HTH
TOndrej
0

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