GregorianToJD

(PHP 4, PHP 5)

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

See Also

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

Коментарии

Автор:
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.
2004-06-08 19:04:03
http://php5.kiev.ua/manual/ru/function.gregoriantojd.html
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;
?>
2005-03-17 15:34:54
http://php5.kiev.ua/manual/ru/function.gregoriantojd.html
Автор:
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);
    }

?>
2009-04-07 16:19:25
http://php5.kiev.ua/manual/ru/function.gregoriantojd.html

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