Main Page | Report this Page
Computers Forum Index  »  Computer - Databases - Oracle  »  Decoding a date & time format...
Page 1 of 1    

Decoding a date & time format...

Author Message
Rob Nicholson...
Posted: Tue Oct 28, 2008 5:00 pm
Guest
Not sure if this is a good place to post, but we're trying to reverse
engineer an Oracle database which has two fields for date & time. They don't
seem to be encoded using the standard Oracle date/time fields so we suspect
the developer has used some bespoke encoding system.

So I thought it would be a good challenge for somebody mathematically
minded.

The example I currently have is:

17th October 2008 encoded as 131598865
13:54:49 encoded as 221655296

I'll try and get some more examples.

Any help appreciated.

Thanks, Rob.
 
Phil Carmody...
Posted: Tue Oct 28, 2008 6:51 pm
Guest
"Rob Nicholson" <rob.nicholson at (no spam) nospan.com> writes:
Quote:
Not sure if this is a good place to post, but we're trying to reverse
engineer an Oracle database which has two fields for date & time. They don't
seem to be encoded using the standard Oracle date/time fields so we suspect
the developer has used some bespoke encoding system.

So I thought it would be a good challenge for somebody mathematically
minded.

The example I currently have is:

17th October 2008 encoded as 131598865

Hexadecimal: 0x07D80A11
And:
07D8 = 2008
0A = 10
11 = 17

Quote:
13:54:49 encoded as 221655296

Hexadecimal: 0x0D363100
And:
0D = 13
36 = 54
31 = 49


Phil

--
Christianity has such a contemptible opinion of human nature that it does
not believe a man can tell the truth unless frightened by a belief in God.
No lower opinion of the human race has ever been expressed.
-- Robert Green Ingersoll (1833-1899), American politician and scientist
 
Jon Slaughter...
Posted: Tue Oct 28, 2008 7:15 pm
Guest
"Phil Carmody" <thefatphil_demunged at (no spam) yahoo.co.uk> wrote in message
news:87abcoesl0.fsf at (no spam) nonospaz.fatphil.org...
Quote:
"Rob Nicholson" <rob.nicholson at (no spam) nospan.com> writes:
Not sure if this is a good place to post, but we're trying to reverse
engineer an Oracle database which has two fields for date & time. They
don't
seem to be encoded using the standard Oracle date/time fields so we
suspect
the developer has used some bespoke encoding system.

So I thought it would be a good challenge for somebody mathematically
minded.

The example I currently have is:

17th October 2008 encoded as 131598865

Hexadecimal: 0x07D80A11
And:
07D8 = 2008
0A = 10
11 = 17

13:54:49 encoded as 221655296

Hexadecimal: 0x0D363100
And:
0D = 13
36 = 54
31 = 49


Phil


Which means it's simply byte byte word format.

i.e., day + month << 8 + year << 16

decoding is in reverse:

day = date & 0xFF;
month = date >> 8 & 0xFF
year = date >> 16
 
Phil Carmody...
Posted: Tue Oct 28, 2008 8:20 pm
Guest
"Jon Slaughter" <Jon_Slaughter at (no spam) Hotmail.com> writes:
Quote:
"Phil Carmody" <thefatphil_demunged at (no spam) yahoo.co.uk> wrote in message
news:87abcoesl0.fsf at (no spam) nonospaz.fatphil.org...
"Rob Nicholson" <rob.nicholson at (no spam) nospan.com> writes:
Not sure if this is a good place to post, but we're trying to reverse
engineer an Oracle database which has two fields for date & time. They
don't
seem to be encoded using the standard Oracle date/time fields so we
suspect
the developer has used some bespoke encoding system.

So I thought it would be a good challenge for somebody mathematically
minded.

The example I currently have is:

17th October 2008 encoded as 131598865

Hexadecimal: 0x07D80A11
And:
07D8 = 2008
0A = 10
11 = 17

13:54:49 encoded as 221655296

Hexadecimal: 0x0D363100
And:
0D = 13
36 = 54
31 = 49

Which means it's simply byte byte word format.

i.e., day + month << 8 + year << 16

Not in C, it's not. + has higher precedence than <<.

Phil
--
Christianity has such a contemptible opinion of human nature that it does
not believe a man can tell the truth unless frightened by a belief in God.
No lower opinion of the human race has ever been expressed.
-- Robert Green Ingersoll (1833-1899), American politician and scientist
 
Rob Nicholson...
Posted: Tue Oct 28, 2008 9:35 pm
Guest
Quote:
17th October 2008 encoded as 131598865

Hexadecimal: 0x07D80A11
And:
07D8 = 2008
0A = 10
11 = 17

Ah! Thanks - can I buy you a virtual pint via PayPal?

Cheers, Rob.
 
Rob Nicholson...
Posted: Tue Oct 28, 2008 9:45 pm
Guest
Quote:
Ah! Thanks - can I buy you a virtual pint via PayPal?

Email informed.direct at (no spam) googlemail.com - I'm serious!

Cheers, Rob.
 
 
Page 1 of 1    
All times are GMT
The time now is Mon Nov 23, 2009 6:43 am