I worked on this, and managed to finish the translations today.

If anyone would like to contribute by translating please refer to the code bellow, and do the translation. the code below is the Sinhala translation of the module my native language ;)

<?php

/**
 * Sinhalese (Sri Lanka) language pack
 * @package calendar
 */


$lang['si_LK']['CalendarHolder']['JAN'] = 'ජන';
$lang['si_LK']['CalendarHolder']['FEB'] = 'පෙබ';
$lang['si_LK']['CalendarHolder']['MAR'] = 'මාර්';
$lang['si_LK']['CalendarHolder']['APR'] = 'අප්';
$lang['si_LK']['CalendarHolder']['MAY'] = 'මැයි';
$lang['si_LK']['CalendarHolder']['JUN'] = 'ජුනි';
$lang['si_LK']['CalendarHolder']['JUL'] = 'ජූලි';
$lang['si_LK']['CalendarHolder']['AUG'] = 'අගෝ';
$lang['si_LK']['CalendarHolder']['SEP'] = 'සැප්';
$lang['si_LK']['CalendarHolder']['OCT'] = 'ඹක්';
$lang['si_LK']['CalendarHolder']['NOV'] = 'නොවෙ';
$lang['si_LK']['CalendarHolder']['DEC'] = 'දෙසැ';

$lang['si_LK']['CalendarHolder']['SUN'] = 'සදු';
$lang['si_LK']['CalendarHolder']['MON'] = 'සදු';
$lang['si_LK']['CalendarHolder']['TUE'] = 'අග';
$lang['si_LK']['CalendarHolder']['WED'] = 'බුද';
$lang['si_LK']['CalendarHolder']['THU'] = 'බ්රහස්';
$lang['si_LK']['CalendarHolder']['FRI'] = 'සිකු';
$lang['si_LK']['CalendarHolder']['SAT'] = 'සෙන';

$lang['si_LK']['CalendarHolder']['JANUARY'] = 'ජනවාරි';
$lang['si_LK']['CalendarHolder']['FEBRUARY'] = 'පෙබරවාරි';
$lang['si_LK']['CalendarHolder']['MARCH'] = 'මාර්තු';
$lang['si_LK']['CalendarHolder']['APRIL'] = 'අප්රේල්';
$lang['si_LK']['CalendarHolder']['MAY'] = 'මැයි';
$lang['si_LK']['CalendarHolder']['JUNE'] = 'ජුනි';
$lang['si_LK']['CalendarHolder']['JULY'] = 'ජූලි';
$lang['si_LK']['CalendarHolder']['AUGUST'] = 'අගෝස්තු';
$lang['si_LK']['CalendarHolder']['SEPTEMBER'] = 'සැප්තැම්බර්';
$lang['si_LK']['CalendarHolder']['OCTOBER'] = 'ඹක්තෝබර්';
$lang['si_LK']['CalendarHolder']['NOVEMBER'] = 'නොවැම්බර්';
$lang['si_LK']['CalendarHolder']['DECEMBER'] = 'දෙසැම්බර්';

$lang['si_LK']['CalendarHolder']['NEXT'] = 'ඊලග';
$lang['si_LK']['CalendarHolder']['PRE'] = 'ගිය';

?>

I will post the module soon after some last tests.

Hey Nivanka, looks like the forum chokes a bit on the special characters in your translation (or is it just my browser?).
I'd suggest using translate.silverstripe.com for your module, feel free to submit a language file there (you can update it as required).

Hi Ingo,

I think this happens because you have not got the correct unicode set installed.

Anyway Here are the words which need to be translated.

JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC

SUN
MON
TUE
WED
THU
FRI
SAT

JANUARY
FEBRUARY
MARCH
APRIL
MAY
JUNE
JULY
AUGUST
SEPTEMBER
OCTOBER
NOVEMBER
DECEMBER

NEXT
PRE

I will add the language file to the translate.silverstripe.com soon after I get the new version on the module directory.

Hi, I've attached the swedish calendar translation. Enjoy.

Nice one pmnordkvist,

I will add it to the module. Thanks for the good work

Here is the german translation.
Tested it on local installation works fine.

Peter

Hi Peter,

Thanks for the god work. I will add this to the module and post it again soon. Keep it up.

I've attached the dutch calendar translation. Enjoy.