Converting Cobol date to .Net DateTime

[Alexf2]

Hello!

I'm reading binary file exported from mainframe's tape. There used COBOL data types. Some date fields are represented by PIC '9999', but some - by FIXED(7). The first one I have recognized and converted quickly, but the second one is a problem.

I found the conversion algorithm (http://www.thescripts.com/forum/thread267116.html) to convert FIXED(7) to UInt32 value, but now I don't know how to construct .Net DateTime from this UInt32.

Have somebody had deal with this problem? I tried distinct binary loayouts of date (http://webster.cs.ucr.edu/AoA/Windows/HTML/DataRepresentationa7.html), but I didn't get result seeming correctly.


I tried to get UInt32 by two ways:

private static UInt32 IntFromFixed( Byte[] raw )
{
Int32 res = 0;
Byte b;
for( Int32 i = 0; i < raw.Length - 1; ++i )
{
res <<= 8;
b = raw[ i ];
res += ((b & 0xF) + (b >> 4)*10);
}
b = raw[ raw.Length - 1 ];
res <<= 8;
res += ((b >> 4)*10);
b &= 0xF;
if( b == 0xD )
res = -res;

return res;
}

OR
private static UInt32 IntFromFixed( Byte[] raw )
{
String res = "";
Byte b;
for( Int32 i = 0; i < raw.Length - 1; ++i )
{
b = raw[ i ];
res += ((b & 0xF) + (b >> 4)*10).ToString();
}
b = raw[ raw.Length - 1 ];
res += ((b >> 4)*10).ToString();
b &= 0xF;
if( b == 0xD )
res = "-" + res;

return UInt32.Parse( res );
}

And I tried to construct DateTime:

UInt32 dc = IntFromFixed( raw );
UInt32 y = (dc & 0x7F), m = (dc & 0xF000) >> 12, d = (dc & 0xF80) >> 7;
if( y == 0 )
return (DateTime?)null;
return (DateTime?)new DateTime( 1900 + (int)y, (int)m, (int)d );



Thanks and good luck!