I have writed into CI-Forum the solution for Traslated date, but I have revised and release new version here:
Open “application/helpers/language_helper.php” and add this function:
function localize_date($db_datetime, $datetime_format = NULL)
{
// Setup date and time format from options.
if ( $datetime_format === NULL )
{
$formatted_date = strftime('%d %B, %Y', strtotime($db_datetime));
}
else
{
$formatted_date = strftime($datetime_format, strtotime($db_datetime));
}
// Load CI and language file.
$ci =& get_instance();
$ci->lang->load('calendar');
$search = array( 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday',
'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun',
'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December',
'Jan', 'Feb', 'Mar', 'Apr', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec',
'1st', '2nd', '3rd', '4th', '5th', '6th', '7th', '8th', '9th', '10th', '11th', '12th', '13th', '14th', '15th', '16th', '17th', '18th', '20th', '21st', '22nd', '23rd', '24th', '25th', '26th', '27th', '28th', '29th', '30th', '31st');
$replace = array( $ci->lang->line('cal_monday'), $ci->lang->line('cal_tuesday'), $ci->lang->line('cal_wednesday'), $ci->lang->line('cal_thursday'), $ci->lang->line('cal_friday'), $ci->lang->line('cal_saturday'), $ci->lang->line('cal_sunday'),
$ci->lang->line('cal_mon'), $ci->lang->line('cal_tue'), $ci->lang->line('cal_wed'), $ci->lang->line('cal_thu'), $ci->lang->line('cal_fri'), $ci->lang->line('cal_sat'), $ci->lang->line('cal_sun'),
$ci->lang->line('cal_january'), $ci->lang->line('cal_february'), $ci->lang->line('cal_march'), $ci->lang->line('cal_april'), $ci->lang->line('cal_may'), $ci->lang->line('cal_june'), $ci->lang->line('cal_july'), $ci->lang->line('cal_august'), $ci->lang->line('cal_september'), $ci->lang->line('cal_october'), $ci->lang->line('cal_november'), $ci->lang->line('cal_december'),
$ci->lang->line('cal_jan'), $ci->lang->line('cal_feb'), $ci->lang->line('cal_mar'), $ci->lang->line('cal_apr'), $ci->lang->line('cal_jun'), $ci->lang->line('cal_jul'), $ci->lang->line('cal_aug'), $ci->lang->line('cal_sep'), $ci->lang->line('cal_oct'), $ci->lang->line('cal_nov'), $ci->lang->line('cal_dec'),
$ci->lang->line('dblog_date_1'), $ci->lang->line('dblog_date_2'), $ci->lang->line('dblog_date_3'), $ci->lang->line('dblog_date_4'), $ci->lang->line('dblog_date_5'), $ci->lang->line('dblog_date_6'), $ci->lang->line('dblog_date_7'), $ci->lang->line('dblog_date_8'), $ci->lang->line('dblog_date_9'), $ci->lang->line('dblog_date_10'), $ci->lang->line('dblog_date_11'), $ci->lang->line('dblog_date_12'), $ci->lang->line('dblog_date_13'), $ci->lang->line('dblog_date_14'), $ci->lang->line('dblog_date_15'), $ci->lang->line('dblog_date_16'), $ci->lang->line('dblog_date_17'), $ci->lang->line('dblog_date_18'), $ci->lang->line('dblog_date_19'), $ci->lang->line('dblog_date_20'), $ci->lang->line('dblog_date_21'), $ci->lang->line('dblog_date_22'), $ci->lang->line('dblog_date_23'), $ci->lang->line('dblog_date_24'), $ci->lang->line('dblog_date_25'), $ci->lang->line('dblog_date_26'), $ci->lang->line('dblog_date_27'), $ci->lang->line('dblog_date_28'), $ci->lang->line('dblog_date_29'), $ci->lang->line('dblog_date_30'), $ci->lang->line('dblog_date_31'));
return str_replace($search, $replace, $formatted_date);
}
This function get from “dBlog”, another blog software writed with CodeIgniter.
And now is very simple to change datetime in your language (if you have added), where found this:
<?php echo strftime('%d %B, %Y ' . lang('at') . ' %H:%M:%S', strtotime($comment['date'])); ?>
Is simple, change with this:
<?php echo localize_date($comment['date'], '%d %B, %Y ' . lang('at') . ' %H:%M:%S'); ?>
Or if you want use the standard format:
<?php echo localize_date($comment['date']); ?>
I like this method, please add into the core the possible to traslate date 
