   #PHP Manual Calendar functions easter_date FrenchToJD

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                                  easter_days

   (PHP 3>= 3.0.9, PHP 4 )
   easter_days --  Get number of days after March 21 on which Easter
   falls for a given year

Description

   int easter_days ( [int year [, int method]])

   Returns the number of days after March 21 on which Easter falls for a
   given year. If no year is specified, the current year is assumed.

   Since PHP 4.3.0, the year parameter is optional and defaults to the
   current year according to the localtime if omitted.

   The method parameter was also introduced in PHP 4.3.0 and allows to
   calculate easter dates based on the Gregorian calendar during the
   years 1582 - 1752 when set to CAL_EASTER_ROMAN. See the calendar
   constants for more valid constants.

   This function can be used instead of easter_date() to calculate Easter
   for years which fall outside the range of Unix timestamps (i.e. before
   1970 or after 2037).

   Example 1. easter_days() example
   <?php
   echo easter_days(1999);        // 14, i.e. April 4
   echo easter_days(1492);        // 32, i.e. April 22
   echo easter_days(1913);        //  2, i.e. March 23
   ?>

   The date of Easter Day was defined by the Council of Nicaea in AD325
   as the Sunday after the first full moon which falls on or after the
   Spring Equinox. The Equinox is assumed to always fall on 21st March,
   so the calculation reduces to determining the date of the full moon
   and the date of the following Sunday. The algorithm used here was
   introduced around the year 532 by Dionysius Exiguus. Under the Julian
   Calendar (for years before 1753) a simple 19-year cycle is used to
   track the phases of the Moon. Under the Gregorian Calendar (for years
   after 1753 - devised by Clavius and Lilius, and introduced by Pope
   Gregory XIII in October 1582, and into Britain and its then colonies
   in September 1752) two correction factors are added to make the cycle
   more accurate.

   (The code is based on a C program by Simon Kershaw, <webmaster at
   ely.anglican dot org>)

   See also easter_date().
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