Converting traditional Japanese era year into Gregorian year

Question

The traditional Japanese calendar consists of eras based on the reigning emperors. The imperial date format is required for some government documents and appl

Answer 1

You just have to use IntlDateFormatter::parse:

<?php
$formatter = new IntlDateFormatter(
    'ja_JP@calendar=japanese',
    IntlDateFormatter::FULL,
    IntlDateFormatter::FULL,
    'Europe/Madrid',
    IntlDateFormatter::TRADITIONAL,
    'Gy' //Age and year (regarding the age)
);
$r = $formatter->format(strtotime('2012-01-01 Europe/Madrid'));
echo "Age in Japanese: $r\n";
$time = $formatter->parse($r);
$gregCalendar = IntlCalendar::createInstance('Europe/Madrid', 'ja_JP');
$gregCalendar->setTime($time * 1000);
$r2 = IntlDateFormatter::formatObject($gregCalendar, 'Gy');
echo "And back: $r2\n";

gives:

Age in Japanese: 平成24
And back: AD2012