Need to change the date formatting mask. This solution is for many languages.
1. Open file "sappire\core\model\fieldtypes\Date.php"
2. Replace function "date" and formatting mask with strftime function (see more http://www.php.net/manual/en/function.strftime.php)
3. Open your "_config.php" file and add this string: setlocale(LC_TIME,''); or setlocale(LC_TIME, 'your_LOCAL');
Next you need to have a regional file be present for the desired language. At the moment these are not (yet) included in the SilverStripe distribution. Get them here: http://jquery-ui.googlecode.com/svn/trunk/ui/i18n/
SilverStripe expects this file to live in /framework/thirdparty/jquery-ui/minified/i18n/jquery.ui.datepicker-nl.min.js (note the .min in the name)
My issue isn't the exact same, but it is an issue with the calendar picker.
If the calendar picker field is required, I'm finding when I pick the date with the jquery calendar, it fills the field in fine, but when I go to submit the form the JS validation says that the form is required and needs to be filled out.
Has anybody experienced this before? I've had clients tell me the same and I can replicate it.
I'm just using the userforms module, and setting the date in my config file as i18n::set_date_format('dd/MM/YYYY');