CCalendar::OnSocNetGroupDelete

static function OnSocNetGroupDelete($groupId)
{
	$groupId = (int)$groupId;
	if ($groupId > 0)
	{
		$res = CCalendarSect::GetList(
			array(
				'arFilter' => array(
					'CAL_TYPE' => 'group',
					'OWNER_ID' => $groupId,
				),
				'checkPermissions' => false,
			)
		);

		foreach($res as $sect)
		{
			CCalendarSect::Delete($sect['ID'], false);
		}
	}
	return true;
}