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JDDayOfWeek> <FrenchToJD
Last updated: Fri, 20 Nov 2009

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GregorianToJD

(PHP 4, PHP 5)

GregorianToJDConverts a Gregorian date to Julian Day Count

Descrierea

int gregoriantojd ( int $month , int $day , int $year )

Valid Range for Gregorian Calendar 4714 B.C. to 9999 A.D.

Although this function can handle dates all the way back to 4714 B.C., such use may not be meaningful. The Gregorian calendar was not instituted until October 15, 1582 (or October 5, 1582 in the Julian calendar). Some countries did not accept it until much later. For example, Britain converted in 1752, The USSR in 1918 and Greece in 1923. Most European countries used the Julian calendar prior to the Gregorian.

Parametri

month

The month as a number from 1 (for January) to 12 (for December)

day

The day as a number from 1 to 31

year

The year as a number between -4714 and 9999

Valorile întroarse

The julian day for the given gregorian date as an integer.

Exemple

Example #1 Calendar functions

<?php
$jd 
GregorianToJD(10111970);
echo 
"$jd\n";
$gregorian JDToGregorian($jd);
echo 
"$gregorian\n";
?>

Vedeţi de asemenea

  • jdtogregorian() - Converts Julian Day Count to Gregorian date
  • cal_to_jd() - Converts from a supported calendar to Julian Day Count



JDDayOfWeek> <FrenchToJD
Last updated: Fri, 20 Nov 2009
 
add a note add a note User Contributed Notes
GregorianToJD
jfg
07-Apr-2009 08:19
If you need the same output as the g_date_get_julian function of the GlibC, here is my php implementation :

<?php
   
/**
     * Glib g_date_get_julian PHP implementation
     *
     * @param  $str  Date string in a format accepted by strtotime
     * @author jfg
     */
   
private function _get_julian( $str )
    {
       
$d = date_create($str);

        if(
$d == false )
            return
0;
       
       
$day_in_year = (int) date_format($d, "z");
       
$year        = (int) date_format($d, "Y") - 1;
       
$julian_days = $year * 365;
       
$julian_days += ($year >>= 2);
       
$julian_days -= ($year /= 25);
       
$julian_days += $year >> 2;
       
$julian_days += $day_in_year + 1;

        return
ceil($julian_days);
    }

?>
ryker at ridgex dot net
06-Jun-2006 03:27
<?php
/*
* ComputeDateDifference(...)
*   Description:
*     Calculates the difference between two dates.
*
*   Parameter:
*     $m0, $d0, $y0   => 1. Moth/Day/Year
*     $m1, $d1, $y1   => 2. Moth/Day/Year
*
*   Return:
*     Difference between given dates in days.
*
*   Autor:
*     06.06.2006 - Christian Meyer <ryker@ridgex.net>
*/
function ComputeDateDifference($m0,$d0,$y0,$m1,$d1,$y1)
{
 
$x0 = gregoriantojd($m0,$d0,$y0);
 
$x1 = gregoriantojd($m1,$d1,$y1); 
 
 
$diff = $x1 - $x0;
 
  if (
$diff < 0)
   
$diff *= -1; // abs
   
 
return $diff;   
}
?>
jettyrat at jettyfishing dot com
17-Mar-2005 09:34
You can obtain the decimal fraction of the Julian date with the php gregoriantojd() function or the function shown below by applying this code to the returned value.

<?php
  $julianDate
= gregoriantojd($month, $day, $year);

 
//correct for half-day offset
 
$dayfrac = date('G') / 24 - .5;
  if (
$dayfrac < 0) $dayfrac += 1;

 
//now set the fraction of a day
 
$frac = $dayfrac + (date('i') + date('s') / 60) / 60 / 24;

 
$julianDate = $julianDate + $frac;
?>
httpwebwitch
08-Jun-2004 11:04
This function also ignores decimal fractions in JD dates, and it uses non-standard format for returning the Gregorian date.

So, if your JD date is 2453056.28673, the Gregorian returned value is 2/20/2004, not "2004-02-20 23:45:36"

The decimal part is important, since the Julian day begins at noon, for example 2453056.49 is on Friday, 2453056.50 is on Saturday. Discarding the decimal part means that your returned Gregorian Date will be wrong 50% of the time.

JDDayOfWeek> <FrenchToJD
Last updated: Fri, 20 Nov 2009
 
 
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