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are two classes for replacement
. Instead of using a
for storing the date, it uses a 64 bit
integer to store the date and time. The range is +/-29000 years and the smallest time span is 0.1 microseconds.
As "everybody" knows that accuracy of floating point is not so good with small values.
My experience says
can not handle 1 second time and spans
correctly. Sometimes I would get:
(2sec-1sec) != 1sec
... This was not what I wanted!
Secondly, the resolution for
COleDateTime is only 1 second and I needed better.
CHighTime(Span) handle down to 0.1 microsecond. I choose this because
FILETIME and the
KeQuerySystemTime function in the kernel
use this resolution. One strange thing is that they have zero time at January 1, 1601.
But I follow that convention for easy integration.
Finally, I needed to calculate time in a kernel driver and there floating point maths
not possible. There are some changes that are needed to do before it is possible to use
it in a driver. All MFC use must be also removed. I have started but haven't finished it.
It should also be possible to use the classes in a non MFC project with some small not yet
implemented parts...See below
CHighTime(Span) is quite simple and similar to
Include CHighTime.h where you need it and create an instance of
There are some different constructors. Both with separate date/time parts and with
FILETIME as arguments. The output format string is the same as for
_tcsftime with additional codes for millisec(%s), microsec(%u), nanosec(%n).
CHighTimeSpan is also
capable of handling "out of range" values. eg. 30 hours =
> 1 day + 6 hours
The constructors have milli, micro, nano default value 0 so it is possible to replace
COleDateTime directly without any changes.
CHighTime PresentTime, SomeTime;
CHighTimeSpan TheLife, OneDay(1,0,0,0);
PresentTime = CHighTime::GetPresentTime();
SomeTime = CHighTime(1968, 6, 8, 0, 2, 0);
TheLife = PresentTime - SomeTime;
sText = TheLife.Format(
"I have lived %D days %H hours %M minutes %S seconds %s milliseconds\n"
systime = CHighTime(2000,1,13, 14,07,10, 20, 40, 100);
SomeTime.SetDateTime(2000, 1, 13, 14, 25, 10);
sText.Format("The time now is %s\n", (LPCTSTR)PresentTime.Format("%H:%M:%S:%s"));
"The date tomorrow is %s\n",
If you want to use the class in a MFC project, add
before the include of hightime.h, in the hightime.cpp like
Things to improve
- Modify so a kerneldriver can use the classes. The string functions must be removed/changed.
The only need for the
CHighTime::Format function should be for trace.
So why make that work for almost nothing....??? A additional #define could be used for using
the classes in a driver
Please feel free to send me any suggestions about these classes.