DWORD date value

[Lee K]

This is not strictly a C++ issue but if anyone will know the answer its you
guys!

I am trying to figure out a date format stored in the registry by a piece of
software (I am trying to write something to enable me to script a
configuration). The program stores a createdate for a set of registry keys
held in a DWORD value. I assumed it would be the number of seconds since
epoch (1/1/1970 00:00:00) - but its not. Here is a couple of examples:

19/12/2002 11:41:38 = 764632371
13/12/2002 11:36:58 = 764239005

Any one have any other ideas????

Thanks

Lee

[Victor Bazarov]

Re: DWORD date value

"Lee K" <notme@nothere. com> wrote...[color=blue]
> This is not strictly a C++ issue but if anyone will know the answer its[/color]
you[color=blue]
> guys!
>
> I am trying to figure out a date format stored in the registry by a piece[/color]
of[color=blue]
> software (I am trying to write something to enable me to script a
> configuration). The program stores a createdate for a set of registry[/color]
keys[color=blue]
> held in a DWORD value. I assumed it would be the number of seconds since
> epoch (1/1/1970 00:00:00) - but its not. Here is a couple of examples:
>
> 19/12/2002 11:41:38 = 764632371
> 13/12/2002 11:36:58 = 764239005
>
> Any one have any other ideas????[/color]

Looks like your DWORD is a (<date> << 16) + <time>. Perhaps even
the regular packed MSDOS date and time values. Remember those?

bits:

Date: YYYYYYYMMMMDDDD D
Time: HHHHHMMMMMMSSSS S, where S is half of real seconds.

So, to calculate the date you need to do

void breakDate(DWORD dvalue, int& year, int& month, int& day,
int& hour, int& minute, int& sec)
{
year = (dvalue >> 25) + 1980;
month = (dvalue >> 21) & 0xf;
day = (dvalue >> 16) & 0x1f;
hour = (dvalue >> 11) & 0x1f;
minute = (dvalue >> 5) & 0x3f;
sec = (dvalue & 0x1f) * 2;
}

It's possible to have invalid values. Month can be more than 12,
day can be more than the nubmer of days in the month, hours could
be > 23, minutes can be > 59, seconds could be > 59.

Victor

[Lee K]

Re: DWORD date value

You are right - thank you very much.

What is the best way to actually create the DWORD value from the current
date?

Thanks,

Lee

"Victor Bazarov" <v.Abazarov@att Abi.com> wrote in message
news:vhdtf1o344 bd76@corp.super news.com...[color=blue]
> "Lee K" <notme@nothere. com> wrote...[color=green]
> > This is not strictly a C++ issue but if anyone will know the answer its[/color]
> you[color=green]
> > guys!
> >
> > I am trying to figure out a date format stored in the registry by a[/color][/color]
piece[color=blue]
> of[color=green]
> > software (I am trying to write something to enable me to script a
> > configuration). The program stores a createdate for a set of registry[/color]
> keys[color=green]
> > held in a DWORD value. I assumed it would be the number of seconds[/color][/color]
since[color=blue][color=green]
> > epoch (1/1/1970 00:00:00) - but its not. Here is a couple of examples:
> >
> > 19/12/2002 11:41:38 = 764632371
> > 13/12/2002 11:36:58 = 764239005
> >
> > Any one have any other ideas????[/color]
>
> Looks like your DWORD is a (<date> << 16) + <time>. Perhaps even
> the regular packed MSDOS date and time values. Remember those?
>
> bits:
>
> Date: YYYYYYYMMMMDDDD D
> Time: HHHHHMMMMMMSSSS S, where S is half of real seconds.
>
> So, to calculate the date you need to do
>
> void breakDate(DWORD dvalue, int& year, int& month, int& day,
> int& hour, int& minute, int& sec)
> {
> year = (dvalue >> 25) + 1980;
> month = (dvalue >> 21) & 0xf;
> day = (dvalue >> 16) & 0x1f;
> hour = (dvalue >> 11) & 0x1f;
> minute = (dvalue >> 5) & 0x3f;
> sec = (dvalue & 0x1f) * 2;
> }
>
> It's possible to have invalid values. Month can be more than 12,
> day can be more than the nubmer of days in the month, hours could
> be > 23, minutes can be > 59, seconds could be > 59.
>
> Victor
>
>[/color]

[Victor Bazarov]

Re: DWORD date value

"Lee K" <notme@nothere. com> wrote...[color=blue]
> You are right - thank you very much.
>
> What is the best way to actually create the DWORD value from the current
> date?[/color]

Use << and | operators and just do the reverse of what
I did in the breakDate.

Victor

[Victor Bazarov]

Re: DWORD date value

"Lee K" <notme@nothere. com> wrote...[color=blue]
> Victor,
>
> I tried that but am obviously making a school boy error as it does not[/color]
work,[color=blue]
> any chance you could post an example???[/color]

If we want to make 'XXXKKKKKPPPP' out of three values x, k, and p,
then one approach could be

result = ((x & 7) << 9) | ((k & 31) << 4) | (p & 15);

Can you figure out why '7', '9', '31', '4', and '15'? Let it be
your homework.

Victor

[Lee K]

Re: DWORD date value

Got the answer in the end thanks to Victor!

int yr = 0;
int month = 0;
int day = 0;
int hour = 0;
int minute = 0;
int sec = 0;
CTime n = CTime::GetCurre ntTime();
DWORD dValue = 0;

yr = n.GetYear();
month = n.GetMonth();
day = n.GetDay();
....

dValue = ((yr - 1980) << 25) | ((month & 0xF) << 21) | ((day & 0x1F) << 16)
| ((hour & 0x1F) << 11) | ((minute & 0x3F) << 5) | (sec / 2);

Thank you for your help.... This is why ng's are so great

Lee

"Lee K" <notme@nothere. com> wrote in message
news:3f16ed99$0 $45170$65c69314 @mercury.nildra m.net...[color=blue]
> This is not strictly a C++ issue but if anyone will know the answer its[/color]
you[color=blue]
> guys!
>
> I am trying to figure out a date format stored in the registry by a piece[/color]
of[color=blue]
> software (I am trying to write something to enable me to script a
> configuration). The program stores a createdate for a set of registry[/color]
keys[color=blue]
> held in a DWORD value. I assumed it would be the number of seconds since
> epoch (1/1/1970 00:00:00) - but its not. Here is a couple of examples:
>
> 19/12/2002 11:41:38 = 764632371
> 13/12/2002 11:36:58 = 764239005
>
> Any one have any other ideas????
>
> Thanks
>
> Lee
>
>[/color]

[Victor Bazarov]

Re: DWORD date value

"Lee K" <notme@nothere. com> wrote...[color=blue]
> int yr = 0;
> int month = 0;
> int day = 0;
> int hour = 0;
> int minute = 0;
> int sec = 0;
> CTime n = CTime::GetCurre ntTime();
> DWORD dValue = 0;
>
> yr = n.GetYear();
> month = n.GetMonth();
> day = n.GetDay();
> ...
>
> dValue = ((yr - 1980) << 25) | ((month & 0xF) << 21) | ((day & 0x1F) <<[/color]
16)[color=blue]
> | ((hour & 0x1F) << 11) | ((minute & 0x3F) << 5) | (sec / 2);[/color]

Add some protection to this. Verify that the year you get is,
in fact >= 1980. Otherwise subtracting 1980 from it may lead
to unexpected or even undefined results.

Good luck with your project!

Victor