Internalization timepicker & datepicker inconsequent

In the files: date.php, datetime.php & time.php, located ./inc/fields, a check is done to include the i18n file of either time or date.

// Load localized scripts
$locale = str_replace( '_', '-', get_locale() );
$file_path = 'jqueryui/datepicker-i18n/jquery.ui.datepicker-' . $locale . '.js';

However, the get_locale() function retrieves the either the WPLANG or sets it to en_US. So, if, in our case, we use nl_NL, $locale would become nl-NL, and the file to include would become: jqueryui/datepicker-i18n/jquery.ui.datepicker-nl-NL.js.
Unfortunately, in the ./js/jqueryui/datepicker-i18n/ and /timepicker-i18n/ folder, a lot (but not all) files are coded as e.g. ‘jquery.ui.datepicker-nl.js’. And thus, would the internalization not function properly.

A solution would be renaming the files to ‘jquery.ui.datepicker-nl-NL.js’. There are files which are already renamed like that: e.g. ‘jquery-ui-timepicker-pt-BR.js’.

Besides, jquery.ui.datepicket-nl.js is the only file with still uses an object-like notation, instead of an array-like notation. A patch:

Index: htdocs/wp-content/plugins/meta-box/js/jqueryui/datepicker-i18n/jquery.ui.datepicker-nl.js
===================================================================
--- htdocs/wp-content/plugins/meta-box/js/jqueryui/datepicker-i18n/jquery.ui.datepicker-nl.js	(revision 851182)
+++ htdocs/wp-content/plugins/meta-box/js/jqueryui/datepicker-i18n/jquery.ui.datepicker-nl.js	(working copy)
@@ -1,7 +1,7 @@
 /* Dutch (UTF-8) initialisation for the jQuery UI date picker plugin. */
 /* Written by Mathias Bynens <http://mathiasbynens.be/> */
 jQuery(function($){
-	$.datepicker.regional.nl = {
+	$.datepicker.regional['nl'] = {
 		closeText: 'Sluiten',
 		prevText: '←',
		nextText: '→',
@@ -19,5 +19,5 @@
 		isRTL: false,
 		showMonthAfterYear: false,
 		yearSuffix: ''};
-	$.datepicker.setDefaults($.datepicker.regional.nl);
+	$.datepicker.setDefaults($.datepicker.regional['nl']);
 });

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