convert the list of versions from JIRA into an iCalendar file you can add in Google Calendar

jira-versions-to-ical.php

<?php
$versions_url = 'http://HOSTNAME.atlassian.net/rest/api/2/project/KEY/versions?os_username=USERNAME&os_password=PASSWORD';

$versions_file = file_get_contents($versions_url);

$versions = json_decode($versions_file);

start_calendar();
foreach ($versions as $version) {
    make_event($version);
}
end_calendar();

function start_calendar() {
    echo 'BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//hacksw/handcal//NONSGML v1.0//EN
CALSCALE:GREGORIAN
';
}

function make_event($version) {
    $event = 'BEGIN:VEVENT
SUMMARY:'.$version->{'name'}.'
DESCRIPTION:'.$version->{'description'}.' ('.($version->{'released'}==false ? 'not yet ' : '').'released)
DTSTART:'.dateToCal($version->{'startDate'}).'
DTEND:'.dateToCal($version->{'releaseDate'}).'
END:VEVENT
';
    echo $event;
}

function end_calendar() {
    echo 'END:VCALENDAR';
}

// there is probably a much slicker way of doing this
function dateToCal($time) {
    $date = date_create($time);
    return date_format($date, 'Ymd\This').'Z';
}

?>