jdtogregorian

Example 76. Convert a Julian calendar date to a Gregorian calendar date

// Write a function to add the proper ordinal suffix to a number
function add_ordinal_suffix ($number) {
    $last_2_digits = substr (0, -2, $number);
    if (($number % 10) == 1 && $last_2_digits != 11)
        return $number.'st';
    if (($number % 10) == 2 && $last_2_digits != 12)
        return $number.'nd';
    if (($number % 10) == 3 && $last_2_digits != 13)
        return $number.'rd';
    return $number.'th'; //default suffix
}

/*
    Use the birthdate of Sir Isaac Newton as the Julian calendar date.
    England did not adopt the Gregorian calendar until 1752,
    hence some old texts cite Newton's birthday as December 25, 1642.
*/

// Find the Julian day count for Newton's birthday
$julian_day = juliantojd (12, 25, 1642);

// Find the number of days between today and Newton's birthdate
$difference = unixtojd () - $julian_day;

// Convert $julian_day to a gregorian date
// Parse year, month, and day into separate variables
list ($month, $day, $year) = explode ('/', jdtogregorian ($julian_day));

// Add an ordinal suffix to $month and $day
$day = add_ordinal_suffix ($day);
$month = add_ordinal_suffix ($month);

echo "Sir Isaac Newton was born $difference days ago on the $day day of the $month month of $year.";