FrenchToJD
<?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;
}
?>
GregorianToJD
(PHP 4, PHP 5)
GregorianToJD — Converts a Gregorian date to Julian Day Count
Description
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.
Parameters
- 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
Return Values
The julian day for the given gregorian date as an integer.
Examples
Example #1 Calendar functions
<?php
$jd = GregorianToJD(10, 11, 1970);
echo "$jd\n";
$gregorian = JDToGregorian($jd);
echo "$gregorian\n";
?>
add a note
User Contributed NotesGregorianToJD
ryker at ridgex dot net
06-Jun-2006 12:27
06-Jun-2006 12:27
jettyrat at jettyfishing dot com
17-Mar-2005 06:34
17-Mar-2005 06:34
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 08:04
08-Jun-2004 08:04
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.