Start of week in datepicker in Grappelli admin interface

The Grappelli default datepicker comes with Sunday as the first day of the week. This is really irritating! I want Monday to be the first day of the week for all my present and future models.

Is there a way to do this?

So far, the only "solution" I found involved changing the models' Media class. However, this solution does not seem to work as is with the following:

class Monkey(ImportExportActionModelAdmin):

    class Media:
        js = ("static/i18n/ui.datepicker-en-GB.js")

    ...

Where static/i18n/ui.datepicker-en-GB.js is

(function($) {
    // datepicker, timepicker init
    grappelli.initDateAndTimePicker = function() {

        var options = {
            closeText: "Done",
            prevText: "Prev",
            nextText: "Next",
            currentText: "Today",
            monthNames: [ "January","February","March","April","May","June",
            "July","August","September","October","November","December" ],
            monthNamesShort: [ "Jan", "Feb", "Mar", "Apr", "May", "Jun",
            "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" ],
            dayNames: [ "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday" ],
            dayNamesShort: [ "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat" ],
            dayNamesMin: [ "Su","Mo","Tu","We","Th","Fr","Sa" ],
            weekHeader: "Wk",
            dateFormat: "dd/mm/yy",
            firstDay: 1,
            isRTL: false,
            showMonthAfterYear: false,
            yearSuffix: ""
        };

} )(grp.jQuery);

In any case, this solution is sub-optimal as any new model using a date would have to have the same Meta class defined.

There are indeed a few mistakes in the code above.

First, the AdminModel should be

class Monkey(ImportExportActionModelAdmin):

    class Media:
        js = ("i18n/ui.datepicker-en-GB.js", )

    ...

As the static directory is automatically appended and the js variable must be a tuple -- notice the comma.

Second, the javascrpt I used was a copy-and-paste of the static/grappelli/js/grappelli.js one with the option firstDay: 1, added to the options variable. It reads like so:

(function($) {
    grappelli.initDateAndTimePicker = function() {

        // HACK: get rid of text after DateField (hardcoded in django.admin)
        $('p.datetime').each(function() {
            var text = $(this).html();
            text = text.replace(/^\w*: /, "");
            text = text.replace(/<br>[^<]*: /g, "<br>");
            $(this).html(text);
        });

        var options = {
            firstDay: 1,  // THIS IS THE ONLY CHANGE!!!
            constrainInput: false,
            showOn: 'button',
            buttonImageOnly: false,
            buttonText: '',
            dateFormat: grappelli.getFormat('date'),
            showButtonPanel: true,
            showAnim: '',
            // HACK: sets the current instance to a global var.
            // needed to actually select today if the today-button is clicked.
            // see onClick handler for ".ui-datepicker-current"
            beforeShow: function(year, month, inst) {
                grappelli.datepicker_instance = this;
            }
        };
        var dateFields = $("input[class*='vDateField']:not([id*='__prefix__'])");
        dateFields.datepicker(options);

        if (typeof IS_POPUP != "undefined" && IS_POPUP) {
            dateFields.datepicker('disable');
        }

        // HACK: adds an event listener to the today button of datepicker
        // if clicked today gets selected and datepicker hides.
        // use on() because couldn't find hook after datepicker generates it's complete dom.
        $(document).on('click', '.ui-datepicker-current', function() {
            $.datepicker._selectDate(grappelli.datepicker_instance);
            grappelli.datepicker_instance = null;
        });

        // init timepicker
        $("input[class*='vTimeField']:not([id*='__prefix__'])").grp_timepicker();

    };
})(grp.jQuery);

Thirdly, I modified all the AdminModels that needed a datepicker. This is a PITA and I wish there was a better way of doing it. There might be...