unixtojd

(PHP 4, PHP 5)

unixtojd — Unix zaman damgasını, Jülyen Gün Sayısına çevirir

Açıklama

int unixtojd ([ int $zamandamgasi = time() ] )

Verilen Unix zamandamgasi (1.1.1970'den başlayarak geçen saniye sayısı) için Jülyen Gün Sayısını döndürür, eğer zamandamgasi verilmez ise içinde bulunulan gün için Jülyen Gün Sayısını verir.

Değiştirgeler

zamandamgasi: Çevrilecek unix zaman damgası.

Dönen Değerler

Tamsayı olarak, Jülyen Gün Sayısı.

Ayrıca Bakınız

jdtounix() - Jülyen Gün Sayısını, Unix zaman damgasına çevirir

Tarih ve Zaman

JulianToJD

[edit] Last updated: Fri, 23 Mar 2012

add a note User Contributed Notes unixtojd

Anonymous 20-Mar-2012 09:01


Since upgrading from PHP 5.2.9 to 5.3.10, PHP is throwing the error:



... PHP Fatal error:  Call to undefined function unixtojd() in .../unixtojd.php on line 5



Checking phpinfo(), I can see that the calendar lib is enabled:

'--enable-calendar=shared' 



Searching on Google for posts since the first release of PHP 5.3 (June 30, 2009) did not reveal much more: http://goo.gl/2YbWj



If anyone has an answer, please notify me at lsiden at gmail since I have not found a way to get notified here.



Thank you!

hrabi at linuxwaves dot com 29-Mar-2007 06:02


according to http://www.decimaltime.hynes.net/dates.html#jd and reading "X. Calendar Functions" on this side, it seems that php "jd" is precisely mean as "Chronological Julian Day" (should it be named cjd, and primarily strictly mentioned - isn't it?), used for covnersion between calendar systems. Than it's ok (but Incomplete manual is strongly confusing here IMHO).

Even that, cJD is adjusted to a local time, so... I am rather babeled now, so nothing else :-).

hrabi at linuxwaves dot com 29-Mar-2007 03:33


This is unusable. Julian Day start at noon, not midnight. It's better to use Fabio solution (however there is a lurk problem with leap second).



<?php

function mmd($txt, $str_time) {

   $t = strtotime($str_time);

   $j = unixtojd($t);

   $s = gmstrftime('%D %T %Z', $t);

   $j_fabio = $t / 86400 + 2440587.5;



   printf("${txt} => (%s) %s, %s U, %s J, or %s J<br>\n", $str_time, $s, $t, $j, $j_fabio);

}



//$xt = strtotime("1.1.1970 15:00.00 GMT");

$sam = "9.10.1995 02:00.01 GMT";

$spm = "9.10.1995 22:00.01 GMT";



// unixtojd for $spm returns 2450000 (OK), but for $sam returns 2450000 too! (it is wrong).

mmd("am", $sam);  // should be 2449999 (+ 0.58334)

mmd("pm", $spm);  // should be 2450000 (+ 0.41668)

?>



reference

unix time, and UTC, TAI, ntp, ... problems: http://en.wikipedia.org/wiki/Unix_time

Julian Date Converter: http://aa.usno.navy.mil/data/docs/JulianDate.html

history overview: http://parris.josh.com.au/humour/work/17Nov1858.shtml

fabio at llgp dot org 31-Aug-2006 02:09


If you need an easy way to convert an unix timestamp to a decimal julian day you can use:



$julianDay = $unixTimeStamp / 86400 + 2440587.5;



86400 is the number of seconds in a day;

2440587.5 is the julian day at 1/1/1970 0:00 UTC.

10-Aug-2006 07:22


Its clearly stated that this function returns the Julian Day, not Julian Day + time.



If you want the time with it you will have to do something like:



$t=time();

$jd=unixtojd($t)+($t%60*60*24)/60*60*24;

johnston at capsaicin dot ca 19-Nov-2003 01:43


Also note that epoch is in UTC time (epoch is a specific point in time - epoch is not different for every time zone), so be aware of timezone complexities.

pipian at pipian dot com 12-Jun-2003 09:29


Remember that UNIX timestamps indicate a number of seconds from midnight of January 1, 1970 on the Gregorian calendar, not the Julian Calendar.

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