[edit] Last updated: Fri, 14 Jun 2013

easter_date

(PHP 4, PHP 5)

easter_date — Retorna a data do sistema UNIX correspondente à meia-noite da Páscoa do ano especificado. Se nenhum ano tiver sido especificado, será assumido o ano atual.

Descrição

int easter_date ([ int $ano ] )

Retorna a data do sistema UNIX correspondente à meia-noite da Páscoa do ano especificado. Se nenhum ano tiver sido especificado, será assumido o ano atual.

À partir da versão 4.3.0 PHP, e se omitido o parâmetro ano, o padrão assumido é o ano atual de acordo com a hora local.

Aviso Esta função irá gerar um aviso se o ano está fora do padrão de datas do sistema UNIX (i.e. antes de 1970 ou após 2037).

Exemplo #1 easter_date() exemplo


<?php

echo date ("M-d-Y", easter_date(1999));        // Apr-04-1999
echo date ("M-d-Y", easter_date(2000));        // Apr-23-2000
echo date ("M-d-Y", easter_date(2001));        // Apr-15-2001

?>

A data da Páscoa foi definida pelo Conselho de Nicaea em DC325 como sendo o primeiro domingo após a primeira lua cheia que cai no equinócio da primavera ou depois dele. O equinócio geralmente cai perto do 21º de Março, logo, o cálculo resume-se à determinar a data da lua cheia e a data do seguinte domingo. O algoritmo usado aqui foi feito no ano 532 por Dionysius Exiguus. De acordo com o calendário "Julian" (para anos anterioris à 1753) um simples ciclo de 19-anos é usado para seguir as fases da lua. De acordo com o Calendário Gregoriano (para antes após 1753 - planejado por Clavius e por Lilius, e feito por Pope Gregory XIII em Outubro de 1582, e na Grã Bretanha e suas colônias em Setembro de 1752), duas correções fatoriais foram adicionadas para fazer o ciclo mais exato.

(O código é baseado em um programa feito em C por Simon Kershaw, <webmaster@ely.anglican.org>)

Veja easter_days() para calcular a Páscoa antes de 1970 ou após 2037.

easter_days

cal_to_jd

[edit] Last updated: Fri, 14 Jun 2013

add a note User Contributed Notes easter_date - [8 notes]

down

py dot lebecq at gmail dot com ¶

3 years ago


I recently had to write a function that allows me to know if today is a holiday.



And in France, we have some holidays which depends on the easter date. Maybe this will be helpful to someone.



Just modify in the $holidays array the actual holidays dates of your country.



<?php

/**

 * This function returns an array of timestamp corresponding to french holidays

 */

protected static function getHolidays($year = null)

{

  if ($year === null)

  {

    $year = intval(date('Y'));

  }

    

  $easterDate  = easter_date($year);

  $easterDay   = date('j', $easterDate);

  $easterMonth = date('n', $easterDate);

  $easterYear   = date('Y', $easterDate);



  $holidays = array(

    // These days have a fixed date

    mktime(0, 0, 0, 1,  1,  $year),  // 1er janvier

    mktime(0, 0, 0, 5,  1,  $year),  // Fête du travail

    mktime(0, 0, 0, 5,  8,  $year),  // Victoire des alliés

    mktime(0, 0, 0, 7,  14, $year),  // Fête nationale

    mktime(0, 0, 0, 8,  15, $year),  // Assomption

    mktime(0, 0, 0, 11, 1,  $year),  // Toussaint

    mktime(0, 0, 0, 11, 11, $year),  // Armistice

    mktime(0, 0, 0, 12, 25, $year),  // Noel



    // These days have a date depending on easter

    mktime(0, 0, 0, $easterMonth, $easterDay + 2,  $easterYear),

    mktime(0, 0, 0, $easterMonth, $easterDay + 40, $easterYear),

    mktime(0, 0, 0, $easterMonth, $easterDay + 50, $easterYear),

  );



  sort($holidays);

  

  return $holidays;

}

?>

down

maxie ¶

5 years ago


To compute the correct Easter date for Eastern Orthodox Churches I made a function based on the Meeus Julian algorithm:





<?php


function orthodox_eastern($year) {


    $a = $year % 4;


    $b = $year % 7;


    $c = $year % 19;


    $d = (19 * $c + 15) % 30;


    $e = (2 * $a + 4 * $b - $d + 34) % 7;


    $month = floor(($d + $e + 114) / 31);


    $day = (($d + $e + 114) % 31) + 1;


    


    $de = mktime(0, 0, 0, $month, $day + 13, $year);


    


    return $de;


}


?>

down

Guillaume Dufrene ¶

2 months ago


I found a problem with holidays timestamp computation and daylight saving time.

An article about it at http://goo.gl/76t31 (in french only, sorry).



In summary, this year (2013) easter begins before adding an hour for daylight saving time (occured sunday at 3:00). It means that if you do $easter + X, where x is a number of seconds equivalent to one day, 39 days or 50 days, the result is not equals to a midnight timestamp...



Here a function to check if a midnight timestamp is equals to an holiday :



function isHoliday( $ts ) {

// Licence : Creative Commons (BY)

// By Webpulser - http://goo.gl/76t31

  $fixed_holidays = array( ’01-01′, ’01-05′, ’08-05′, ’14-07′, ’15-08′, ’11-11′, ’25-12′ );

  $format = ‘d-m’;



 $dm = date($format, $ts);

  if ( in_array($dm, $fixed_holidays) ) return true;



 $easter = easter_date( date(‘Y’, $ts) );

  if ( date($format, $easter +   86400) == $dm ) return true;

  if ( date($format, $easter + 3369600) == $dm ) return true;

  if ( date($format, $easter + 4320000) == $dm ) return true;



 return false;

}



feel free to use / modify.

down

luca at musician dot org ¶

1 year ago


Due to range limitations of core functions such as easter_date(), mktime(), strtotime(), I wrote this function to get the Easter Day in string format yyyy-mm-dd.



function myEaster($year)

{

    /*Warning: easter_date(): This function is only valid for years between 1970 and 2037

     * The easter_days() function can be used instead of easter_date() to calculate Easter for years which fall outside the range.

      */

     //The next line would do the work if there were no limitations:

    //return date("Y-m-d",easter_date($year));



    /*Outside range (1970,2037) they advise to use easter_days().

     * Unfortunately, when you have to create a date object as 21-03-yyyy to which add easter_days(), then obtain Easter,

     * functions like strtotime(), DateTime::createFromFormat() will fail. (return value is 01-01-1970)

     */

    $march21=date("$year-03-21");

    $days=easter_days($year);

    if($year<=2037)

    //The next line would do the work if strtotime() wasn't affected by same limitations. But, the if..else is required to handle all years.

        $date = date("Y-m-d",strtotime(date("Y-m-d", strtotime($march21)) . " +$days day"));

    else

    {

        if($days<=10){

            $day=str_pad(21+$days, 2, '0', STR_PAD_LEFT);

            $date=date("$year-03-$day");

        }

        else

        {

            $day=str_pad($days-10, 2, '0', STR_PAD_LEFT);

            $date=date("$year-04-$day");

        }

    }



    return $date;

}

down

peter dot burden at gmail dot com ¶

3 years ago


In 5.3.1 easter_date() returns GMT of start of Easter Day in UK allowing

for UK Summer Time. If you are in another time zone you need to 

calculate offsets.

<?php

        $e1 = easter_date(2008);

        $e2 = easter_date(2009);

        echo "Timestamps " . $e1 . " " . $e2 . "\n";



        //      Timestamps 1206230400 1239490800



        echo "Days between Easter 2008 Easter 2009 = " . ($e2-$e1)/86400 . "\n";



        //      Days between Easter 2008 Easter 2009 = 384.958333333 - i.e. 384 days 23 hours



        date_default_timezone_set("Europe/London");

        echo date( " l, jS F Y H:i TO",$e1) . "\n";

        echo date( " l, jS F Y H:i TO",$e2) . "\n";



        //      Sunday, 23rd March 2008 00:00 GMT+0000

        //      Sunday, 12th April 2009 00:00 BST+0100



        date_default_timezone_set("America/New_York");

        echo date( " l, jS F Y H:i TO",$e1) . "\n";

        echo date( " l, jS F Y H:i TO",$e2) . "\n";



        //      Saturday, 22nd March 2008 20:00 EDT-0400

        //      Saturday, 11th April 2009 19:00 EDT-0400

        //      Daylight saving time in effect - New York 4 hours behind GMT

?>

down

nigelf at esp dot co dot uk ¶

5 years ago


v5.2.1 - There is a known bug with easter_date() that can return incorrect dates for some years:





<?php


// 2008 OK


echo date("D d M Y", easter_date(2008));  // Sun 23 Mar 2008





// 2009 returns Saturday


echo date("D d M Y", easter_date(2009));  // Sat 11 Apr 2009


?>








However easter_days() works correctly:





<?php


echo date("D d M Y", strtotime("2009-03-21 +".easter_days(2009)." days"));  // Sun 12 Apr 2009


?>





It is apparently related to timezone settings.

down

Anonymous ¶

6 years ago


I made the function like this ... works fine !





<?php


function ostern


{


    $maerz21=date('z',mktime(0,0,0,3,21,$jb));





    $d=((15 + $jb/100 - $jb/400 - (8 * $jb/100 + 13) / 25)%30 + 19 * ($jb%19))%30;





    if ($d==29)


    {


        $D=28;


    }


    elseif($d==28 && ($jb%17)>=11)


    {


        $D=27;


    }


    else $D=$d;    





    $e=(2 * ($jb%4) + 4 *($jb%7) + 6 * $D + (6 + $jb/100 - $jb/400 - 2)%7)%7;





    $ostersonntag=$e+$D+1+$maerz21;


    return $ostersonntag;


}


?>

down

phpuser ¶

8 years ago


The algorithm from Bigtree is correct if you add some (int) cast

<?php 

   function easter_date ($Year) { 

   

       /* 

       G is the Golden Number-1 

       H is 23-Epact (modulo 30) 

       I is the number of days from 21 March to the Paschal full moon 

       J is the weekday for the Paschal full moon (0=Sunday, 

         1=Monday, etc.) 

       L is the number of days from 21 March to the Sunday on or before 

         the Paschal full moon (a number between -6 and 28) 

       */ 

       



         $G = $Year % 19; 

         $C = (int)($Year / 100); 

         $H = (int)($C - (int)($C / 4) - (int)((8*$C+13) / 25) + 19*$G + 15) % 30; 

         $I = (int)$H - (int)($H / 28)*(1 - (int)($H / 28)*(int)(29 / ($H + 1))*((int)(21 - $G) / 11)); 

         $J = ($Year + (int)($Year/4) + $I + 2 - $C + (int)($C/4)) % 7; 

         $L = $I - $J; 

         $m = 3 + (int)(($L + 40) / 44); 

         $d = $L + 28 - 31 * ((int)($m / 4)); 

         $y = $Year; 

         $E = mktime(0,0,0, $m, $d, $y); 



         return $E; 



   } 

?>

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