That would be great thanks, much appreciated - details in PM.
*Update: I got it working by adding the following line in the ICS file at line 149:
  private function format_timestamp($timestamp) {
    $dt = new DateTime($timestamp);
    $dt->setTimezone(new DateTimeZone('GMT-1'));
    return $dt->format(self::DT_FORMAT);
  }
Strangely UTC or GMT didn't work but the above does. I note that PHP doesn't advise using GMT-1 as it's only meant for backwards compatibility, so I don't know if there's an alternative I could use? Not urgent for now since it's working, so only if you have a spare minute!

 















