Date to 4 byte string

[Steve]

Hi All,

I have a registration code that currently has 4 bytes that are unused.
I'd like to store a future date in those 4 bytes. Is there a way to
convert a date to a 4 byte string?

When I do something like this,

string stringDate =
DateTime.Parse( "1/15/2210").ToBinary ().ToString("X" );

I get a hex # 15 characters long.

Any suggestions? I only have 4 bytes to work with to stay backward
compatible.

Thanks,
Steve

[Michael A. Covington]

"Steve" <ki****@harpser vices.comwrote in message
news:1b******** *************** *********@4ax.c om...

Hi All,

I have a registration code that currently has 4 bytes that are unused.
I'd like to store a future date in those 4 bytes. Is there a way to
convert a date to a 4 byte string?

Let's see. 4 bytes will hold an unsigned 32-bit integer. Convert the date
into number of days past some specific date, and store it as that.

[Peter Duniho]

On 2007-11-05 09:57:51 -0800, Steve <ki****@harpser vices.comsaid:

Hi All,

I have a registration code that currently has 4 bytes that are unused.
I'd like to store a future date in those 4 bytes. Is there a way to
convert a date to a 4 byte string?

Not in a general purpose way. However, you could easily pick a
specific reference date, and then store the total number of days from
that date as the future date. 4 bytes gives you a 32-bit counter, and
you can represent a date VERY far in the future with that as your
number of days. :)

Actually 32-bits is (as you can see from the above) a pretty large
amount of data for the kind of information you're trying to store. So
depending on your desires and needs, you could waste some space making
the 4 bytes a little more readable and likely still come up with
something usable. For example, one byte each for day of month and
month of year, and then two bytes for the year. That would still allow
you to represent absolute dates (rather than the relative suggested
above) through the year 65535. 65536 if you're willing to take
advantage of the fact that there's no 0 AD.

This all assumes the usual Western Gregorian calendar. Your mileage
may vary depending on other calendars you might use, if any.

Pete

[Ignacio Machin \( .NET/ C# MVP \)]

Hi,

I think you could do it, you could use one byte for the day, one for the
month and you have two for the year.
--
Ignacio Machin
http://www.laceupsolutions.com
Mobile & warehouse Solutions.
"Steve" <ki****@harpser vices.comwrote in message
news:1b******** *************** *********@4ax.c om...

Hi All,

I have a registration code that currently has 4 bytes that are unused.
I'd like to store a future date in those 4 bytes. Is there a way to
convert a date to a 4 byte string?

When I do something like this,

string stringDate =
DateTime.Parse( "1/15/2210").ToBinary ().ToString("X" );

I get a hex # 15 characters long.

Any suggestions? I only have 4 bytes to work with to stay backward
compatible.

Thanks,
Steve

[Alberto Poblacion]

"Michael A. Covington" <[e-mail] e in message
news:ew******** ********@TK2MSF TNGP04.phx.gbl. ..

"Steve" <ki****@harpser vices.comwrote in message
news:1b******** *************** *********@4ax.c om...

>I have a registration code that currently has 4 bytes that are unused.
I'd like to store a future date in those 4 bytes. Is there a way to
convert a date to a 4 byte string?

Let's see. 4 bytes will hold an unsigned 32-bit integer. Convert the
date into number of days past some specific date, and store it as that.

Another possibility: Consider the date as a yyyymmdd string, for
instance, 20071231 (you can chhose a different format, of course, but this
one will be advantageous if you need to sort by date). Then store those 8
digits in your 4 bytes, 2 digits per byte. This will be easier to read than
"number of days from a specified date" if you ever have to look at a hex
dump of your data.

[Morten Wennevik [C# MVP]]

Hi Steve,

This article may give you some clues. It's not written in C#, but the principles are the same. Use >and << for bit manipulation.

[Bit Fields and Packed Data]
http://webster.cs.ucr.edu/AoA/Window...ntationa7.html
On Mon, 05 Nov 2007 18:57:51 +0100, Steve <ki****@harpser vices.comwrote:

Hi All,

I have a registration code that currently has 4 bytes that are unused.
I'd like to store a future date in those 4 bytes. Is there a way to
convert a date to a 4 byte string?

When I do something like this,

string stringDate =
DateTime.Parse( "1/15/2210").ToBinary ().ToString("X" );

I get a hex # 15 characters long.

Any suggestions? I only have 4 bytes to work with to stay backward
compatible.

Thanks,
Steve

--
Happy coding!
Morten Wennevik [C# MVP]

[Jon Skeet [C# MVP]]

Steve <ki****@harpser vices.comwrote:

I have a registration code that currently has 4 bytes that are unused.
I'd like to store a future date in those 4 bytes. Is there a way to
convert a date to a 4 byte string?

One thing no-one else has mentioned: strings aren't comprised of bytes.
They're comprised of *characters*. Now, do you need a 4-byte data
structure of any description, or an actual 4 character string?

If you can use 4 bytes in an arbitrary fashion, using an int is likely
to be the best solution. 4 characters would be a different matter.

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too

[=?Utf-8?B?UGV0ZXIgQnJvbWJlcmcgW0MjIE1WUF0=?=]

Something like this?

int myDate = 20071105;
byte[] b = BitConverter.Ge tBytes(myDate);
Console.WriteLi ne(b.Length.ToS tring() + " bytes."); // reads "4 bytes"
-- Peter
http://www.eggheadcafe.com
unBlog: http://petesbloggerama.blogspot.com
BlogMetaFinder: http://www.blogmetafinder.com

"Steve" wrote:

Hi All,

I have a registration code that currently has 4 bytes that are unused.
I'd like to store a future date in those 4 bytes. Is there a way to
convert a date to a 4 byte string?

When I do something like this,

string stringDate =
DateTime.Parse( "1/15/2210").ToBinary ().ToString("X" );

I get a hex # 15 characters long.

Any suggestions? I only have 4 bytes to work with to stay backward
compatible.

Thanks,
Steve

[Ignacio Machin \( .NET/ C# MVP \)]

Hi Jon,
Nice catch :)

--
Ignacio Machin
http://www.laceupsolutions.com
Mobile & warehouse Solutions.
"Jon Skeet [C# MVP]" <sk***@pobox.co mwrote in message
news:MP******** *************@m snews.microsoft .com...

Steve <ki****@harpser vices.comwrote:

>I have a registration code that currently has 4 bytes that are unused.
I'd like to store a future date in those 4 bytes. Is there a way to
convert a date to a 4 byte string?

One thing no-one else has mentioned: strings aren't comprised of bytes.
They're comprised of *characters*. Now, do you need a 4-byte data
structure of any description, or an actual 4 character string?

If you can use 4 bytes in an arbitrary fashion, using an int is likely
to be the best solution. 4 characters would be a different matter.

--
Jon Skeet - <sk***@pobox.co m>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too

[Peter Duniho]

On 2007-11-05 10:37:47 -0800, Jon Skeet [C# MVP] <sk***@pobox.co msaid:

Steve <ki****@harpser vices.comwrote:

>I have a registration code that currently has 4 bytes that are unused.
I'd like to store a future date in those 4 bytes. Is there a way to
convert a date to a 4 byte string?

One thing no-one else has mentioned: strings aren't comprised of bytes.

That's true.

They're comprised of *characters*.

That's not. :) A string may _comprise_ characters. It's not
_comprised of_ characters, it's _composed of_ characters.

Sorry, pet peeve. But if people keep misusing "comprise" like that,
we're left with a word that used to be a perfectly useful word but
which is now just a useless synonym for "compose".

I hope your editor doesn't let you get away with stuff like that in
your book. :)

Now, do you need a 4-byte data
structure of any description, or an actual 4 character string?

Now that is a very good point. As is sometimes the case, I and others
have fallen into the trap of assuming the OP has asked a question that
correctly reflects what he really wants to do. But you're right, his
question is ambigious and he should clarify whether he has 4 bytes or 4
characters to use.

Interestingly, if the latter then my personal opinion is that his
options are possibly actually more restricted than if he had 4 bytes.
Though the native .NET String format is 2 bytes per character,
typically one would not want to store invalid characters or characters
that wouldn't be correctly represented in some external storage.

So unless he could guarantee the string (assuming it is really a
string) is stored as some Unicode format, he'd want to limit himself to
at least regular, printable 8-bit characters (e.g. the Windows "ANSI"
or similar), if not to the printable subset of 7-bit ASCII. That
significantly would reduce the possible number of combinations
available below what a regular 32-bit binary data value would allow.

Ah...nothing is ever as simple as it first looks. :)

Pete