mktime() and UNIXTIME epoch.

[Sandman]

Hi.

On my Linux RedHat 8 system, I can't obtain dates earlier than 1970 with PHP.
That is, when feeding a function that turns dfates into unixtime, such as
mktime() and strtotime()

print date("Y-m-d", mktime(0,0,0,1, 1,1930));
-> "1969-12-31" (since the result of mktime is "-1")

But date() gets it though, so if I do

print date("Y-m-d", -1000000000);
-> "1938-04-24"

Now, presumably this has something to do with Linux instead of PHP, since doing
this in MySQL doesn't work either:

select unix_timestamp( '1935-12-03');
-> 0

But, when using perl, it works just fine when using Date::Manip:

#!/usr/bin/perl
use Date::Manip;
$date = UnixDate("1945-01-23", "%s");
print $date;
-> -787021200

So, how come MySQL can't do it, PHP can't do it, but somehow perl can? Can I
compile PHP with negative integer date support?

--
Sandman[.net]

[Jochen Daum]

Hi Sandman!

On Wed, 18 Feb 2004 09:59:52 +0100, Sandman <[e-mail] > wrote:

Hi.

On my Linux RedHat 8 system, I can't obtain dates earlier than 1970 with PHP.
That is, when feeding a function that turns dfates into unixtime, such as
mktime() and strtotime()

print date("Y-m-d", mktime(0,0,0,1, 1,1930));
-> "1969-12-31" (since the result of mktime is "-1")

But date() gets it though, so if I do

print date("Y-m-d", -1000000000);
-> "1938-04-24"

Now, presumably this has something to do with Linux instead of PHP, since doing
this in MySQL doesn't work either:

select unix_timestamp( '1935-12-03');
-> 0

But, when using perl, it works just fine when using Date::Manip:

#!/usr/bin/perl
use Date::Manip;
$date = UnixDate("1945-01-23", "%s");
print $date;
-> -787021200

So, how come MySQL can't do it, PHP can't do it, but somehow perl can? Can I
compile PHP with negative integer date support?

I think it depends on the underlying unix libraries. I think a better
approach would IMO to write a library based on the MySQL date
functions (or any other database), which should support date support
from 1908-xxxx or earlier. The SQL-92 functions ar much more
rudimentary than what PHP offers, but with some regexes you should get
something going. For dates before 1908 you should ask anyway "Where?",
I was amazed reading Joe Celko's "SQL for Smarties"

HTH, Jochen

[Sandman]

In article <je************ *************** *****@4ax.com>,
Jochen Daum <[e-mail]> wrote:

Hi.

On my Linux RedHat 8 system, I can't obtain dates earlier than 1970 with
PHP. That is, when feeding a function that turns dfates into unixtime, such
as mktime() and strtotime()

print date("Y-m-d", mktime(0,0,0,1, 1,1930));
-> "1969-12-31" (since the result of mktime is "-1")

But date() gets it though, so if I do

print date("Y-m-d", -1000000000);
-> "1938-04-24"

Now, presumably this has something to do with Linux instead of PHP, since
doing this in MySQL doesn't work either:

select unix_timestamp( '1935-12-03');
-> 0

But, when using perl, it works just fine when using Date::Manip:

#!/usr/bin/perl
use Date::Manip; $date = UnixDate("1945-01-23", "%s"); print $date;
-> -787021200

So, how come MySQL can't do it, PHP can't do it, but somehow perl can? Can
I compile PHP with negative integer date support?

I think it depends on the underlying unix libraries. I think a better
approach would IMO to write a library based on the MySQL date functions (or
any other database), which should support date support from 1908-xxxx or
earlier.

Eh, I don't understand... Are you recommending I use MySQL to obtain dates
earlier than 1970 even though I showed above that MySQL doesn't support it
either...? I am confused.

To recap again. MySQL doesn't support it, PHP doesn't support it, Perl supports
it.

--
Sandman[.net]

[Jochen Daum]

Hi Sandman!

On Wed, 18 Feb 2004 10:51:08 +0100, Sandman <[e-mail] > wrote:

In article <je************ *************** *****@4ax.com>,
Jochen Daum <[e-mail]> wrote:

>Hi.
>
>On my Linux RedHat 8 system, I can't obtain dates earlier than 1970 with
>PHP. That is, when feeding a function that turns dfates into unixtime, such
>as mktime() and strtotime()
>
> print date("Y-m-d", mktime(0,0,0,1, 1,1930));
> -> "1969-12-31" (since the result of mktime is "-1")
>
>But date() gets it though, so if I do
>
> print date("Y-m-d", -1000000000);
> -> "1938-04-24"
>
>Now, presumably this has something to do with Linux instead of PHP, since
>doing this in MySQL doesn't work either:
>
> select unix_timestamp( '1935-12-03');
> -> 0
>
>But, when using perl, it works just fine when using Date::Manip:
>
> #!/usr/bin/perl
> use Date::Manip; $date = UnixDate("1945-01-23", "%s"); print $date;
> -> -787021200
>
>So, how come MySQL can't do it, PHP can't do it, but somehow perl can? Can
>I compile PHP with negative integer date support?

I think it depends on the underlying unix libraries. I think a better
approach would IMO to write a library based on the MySQL date functions (or
any other database), which should support date support from 1908-xxxx or
earlier.

Eh, I don't understand... Are you recommending I use MySQL to obtain dates
earlier than 1970 even though I showed above that MySQL doesn't support it
either...? I am confused.

To recap again. MySQL doesn't support it, PHP doesn't support it, Perl supports
it.

If you look at
http://www.mysql.com/doc/en/Date_and...functions.html

and just do not use any %UNIX% functions, you should be fine. I just
tested

SELECT INTERVAL 1 DAY + '1925-12-31'

and its New Years day 1926.

HTH, Jochen

[Sandman]

In article <5h************ *************** *****@4ax.com>,
Jochen Daum <[e-mail]> wrote:

>On my Linux RedHat 8 system, I can't obtain dates earlier than 1970 with
>PHP. That is, when feeding a function that turns dfates into unixtime,
>such as mktime() and strtotime()
>
> print date("Y-m-d", mktime(0,0,0,1, 1,1930));
> -> "1969-12-31" (since the result of mktime is "-1")
>
>But date() gets it though, so if I do
>
> print date("Y-m-d", -1000000000);
> -> "1938-04-24"
>
>Now, presumably this has something to do with Linux instead of PHP,
>since doing this in MySQL doesn't work either:
>
> select unix_timestamp( '1935-12-03');
> -> 0
>
>But, when using perl, it works just fine when using Date::Manip:
>
> #!/usr/bin/perl
> use Date::Manip; $date = UnixDate("1945-01-23", "%s"); print $date;
> -> -787021200
>
>So, how come MySQL can't do it, PHP can't do it, but somehow perl can?
>Can I compile PHP with negative integer date support?

I think it depends on the underlying unix libraries. I think a better
approach would IMO to write a library based on the MySQL date functions
(or any other database), which should support date support from 1908-xxxx
or earlier.

Eh, I don't understand... Are you recommending I use MySQL to obtain dates
earlier than 1970 even though I showed above that MySQL doesn't support it
either...? I am confused.

To recap again. MySQL doesn't support it, PHP doesn't support it, Perl
supports it.

If you look at http://www.mysql.com/doc/en/Date_and...functions.html

and just do not use any %UNIX% functions, you should be fine. I just tested

SELECT INTERVAL 1 DAY + '1925-12-31'

and its New Years day 1926.

I realize that - but perhaps I was unclear at what I wanted. I WANT the unix
timestamp of a given date.

select unix_timestamp( "1985-01-01");
-> 473382000

select unix_timestamp( "1925-01-01");
-> 0

What that other select SHOULD return is "-1420074000" and THAT's what I want. I
want a function, prefferably in PHP, that will return "-1420074000" when I feed
it with "1925-01-01".

--
Sandman[.net]

[Jochen Daum]

Hi Sandman!

On Wed, 18 Feb 2004 12:00:19 +0100, Sandman <[e-mail] > wrote:

In article <5h************ *************** *****@4ax.com>,
Jochen Daum <[e-mail]> wrote:

>> >On my Linux RedHat 8 system, I can't obtain dates earlier than 1970 with
>> >PHP. That is, when feeding a function that turns dfates into unixtime,
>> >such as mktime() and strtotime()
>> >
>> > print date("Y-m-d", mktime(0,0,0,1, 1,1930));
>> > -> "1969-12-31" (since the result of mktime is "-1")
>> >
>> >But date() gets it though, so if I do
>> >
>> > print date("Y-m-d", -1000000000);
>> > -> "1938-04-24"
>> >
>> >Now, presumably this has something to do with Linux instead of PHP,
>> >since doing this in MySQL doesn't work either:
>> >
>> > select unix_timestamp( '1935-12-03');
>> > -> 0
>> >
>> >But, when using perl, it works just fine when using Date::Manip:
>> >
>> > #!/usr/bin/perl
>> > use Date::Manip; $date = UnixDate("1945-01-23", "%s"); print $date;
>> > -> -787021200
>> >
>> >So, how come MySQL can't do it, PHP can't do it, but somehow perl can?
>> >Can I compile PHP with negative integer date support?
>>
>> I think it depends on the underlying unix libraries. I think a better
>> approach would IMO to write a library based on the MySQL date functions
>> (or any other database), which should support date support from 1908-xxxx
>> or earlier.
>
>Eh, I don't understand... Are you recommending I use MySQL to obtain dates
>earlier than 1970 even though I showed above that MySQL doesn't support it
>either...? I am confused.
>
>To recap again. MySQL doesn't support it, PHP doesn't support it, Perl
>supports it.
If you look at http://www.mysql.com/doc/en/Date_and...functions.html

and just do not use any %UNIX% functions, you should be fine. I just tested

SELECT INTERVAL 1 DAY + '1925-12-31'

and its New Years day 1926.

I realize that - but perhaps I was unclear at what I wanted. I WANT the unix
timestamp of a given date.

select unix_timestamp( "1985-01-01");
-> 473382000

select unix_timestamp( "1925-01-01");
-> 0

Thats because the Unix Epoch is from 1970 to 2038. The result is IMO
undefined for dates outside.

What that other select SHOULD return is "-1420074000" and THAT's what I want. I
want a function, prefferably in PHP, that will return "-1420074000" when I feed
it with "1925-01-01".

Its an understandable opinion, but I would dicuss it with the guys
that do the unix date libraries. That might clear it.

HTH, Jochen

--
Jochen Daum - Cabletalk Group Ltd.
PHP DB Edit Toolkit -- PHP scripts for building
database editing interfaces.
http://sourceforge.net/projects/phpdbedittk/

[Sandman]

In article <f7************ *************** *****@4ax.com>,
Jochen Daum <jo*********@ca ns.co.nz> wrote:

I realize that - but perhaps I was unclear at what I wanted. I WANT the unix
timestamp of a given date.

select unix_timestamp( "1985-01-01");
-> 473382000

select unix_timestamp( "1925-01-01");
-> 0

Thats because the Unix Epoch is from 1970 to 2038. The result is IMO
undefined for dates outside.

Well, the unix epoch is system-dependant, on some unix systems it's frm 1970,
and from some it's 1904. It all depends on whether the date integer can handle
inverse values (i.e. 0 is 1970-01-01 00:00:00 and -1 is 1969-12-31 23:59:59).
It's the scope of a 32 bit integer.

What that other select SHOULD return is "-1420074000" and THAT's what
I want. I want a function, prefferably in PHP, that will return
"-1420074000" when I feed it with "1925-01-01".

Its an understandable opinion, but I would dicuss it with the guys
that do the unix date libraries. That might clear it.

Yes, it seems they don't use the system date functions, and I was hoping to
find a way to make PHP do the same... :/

--
Sandman[.net]

[boclair]

"Sandman" <[e-mail] > wrote in message
news:mr******** **************@ news.fu-berlin.de...

In article <f7************ *************** *****@4ax.com>,
Jochen Daum <jo*********@ca ns.co.nz> wrote:

What that other select SHOULD return is "-1420074000" and THAT's what
I want. I want a function, prefferably in PHP, that will return
"-1420074000" when I feed it with "1925-01-01".

it seems they don't use the system date functions, and I was hoping to
find a way to make PHP do the same... :/

How about returning -1420052400 instead?

Have you looked at ADOdb?

I've a scratch page with various conversions at
http://www.boclair.com/adodb_test-time2.php.

Louise

[Sandman]

In article <c1************ *@ID-210679.news.uni-berlin.de>,
"boclair" <bo*****@bigpon d.net.au> wrote:

> What that other select SHOULD return is "-1420074000" and THAT's what
> I want. I want a function, prefferably in PHP, that will return
> "-1420074000" when I feed it with "1925-01-01".

it seems they don't use the system date functions, and I was hoping to
find a way to make PHP do the same... :/

How about returning -1420052400 instead?

Have you looked at ADOdb?

I've a scratch page with various conversions at
http://www.boclair.com/adodb_test-time2.php.

Hello - that looks nice!

What is ADOdb? How do I get the adodb.inc.php file?

--
Sandman[.net]

[boclair]

"Sandman" <[e-mail] > wrote in message
news:mr******** **************@ news.fu-berlin.de...

In article <c1************ *@ID-210679.news.uni-berlin.de>,
"boclair" <bo*****@bigpon d.net.au> wrote:
What is ADOdb? How do I get the adodb.inc.php file?

A GPL program consisting of libraries and PHP classes which standardizes
access across many (most) database programs. Does much more than just
date/time conversions. Very powerful.

See http://php.weblogs.com/adodb .

To begin you might find the following useful.
http://www.phpfreaks.com/tutorials/110/0.php

Louise