Trilium Calendar: Set Sunday as first weekday

calendarSundayFirst.js

// Move "SUN" to first day of week
$('.calendar-week').children().last().prependTo('.calendar-week')

let marginStep = 14.28;
let config = {
    childList: true,
    subtree: true
}

let callback = (mutationList, observer) => {
    let date = new Date($('.calendar-body').children().first().attr('data-calendar-date'));
    let weekday = date.getDay();
    let newMargin = weekday * marginStep;
    $('.calendar-body').children().first().css('margin-left', `${newMargin}%`);
}

let target = $('.calendar-dropdown-widget')[0];

let observer = new MutationObserver(callback);
observer.observe(target, config);