Decoding a date & time format

[Rob Nicholson]

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]

Post by Rob Nicholson
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.
17th October 2008 encoded as 131598865

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

Post by Rob Nicholson
13:54:49 encoded as 221655296

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


Phil

[Jon Slaughter]

Post by Phil Carmody

Post by Rob Nicholson
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.
17th October 2008 encoded as 131598865

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

Post by Rob Nicholson
13:54:49 encoded as 221655296

Hexadecimal: 0x0D363100
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]

Post by Jon Slaughter

Post by Phil Carmody

Post by Rob Nicholson
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.
17th October 2008 encoded as 131598865

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

Post by Rob Nicholson
13:54:49 encoded as 221655296

Hexadecimal: 0x0D363100
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

[Rob Nicholson]

Post by Phil Carmody

Post by Rob Nicholson
17th October 2008 encoded as 131598865

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

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

Cheers, Rob.

[Rob Nicholson]

Post by Rob Nicholson
Ah! Thanks - can I buy you a virtual pint via PayPal?

Email ***@googlemail.com - I'm serious!

Cheers, Rob.

[William Elliot]

Post by Phil Carmody

Post by Rob Nicholson
17th October 2008 encoded as 131598865

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

There's a connection between 131598865 and 0x07D80A11 ?

Post by Phil Carmody

Post by Rob Nicholson
13:54:49 encoded as 221655296

Hexadecimal: 0x0D363100
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

[Phil Carmody]

Post by William Elliot

Post by Phil Carmody

Post by Rob Nicholson
17th October 2008 encoded as 131598865

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

There's a connection between 131598865 and 0x07D80A11 ?

What do you get when you convert 131598865 to hexadecimal?

Sheesh.

Phil