new design and added class function

utils.js

@@ -0,0 +1,34 @@
+export function getWeekdaysForLocale(localeName = 'en-GB', weekday = 'long', firstDayInWeek = 'Sunday') {
+    const {format} = new Intl.DateTimeFormat(localeName, {weekday})
+    const year = firstDayInWeek === 'Sunday' ? 2023 : firstDayInWeek === 'Monday' ? 2022 : 2023
+    const month = firstDayInWeek === 'Sunday' ? 4 : firstDayInWeek === 'Monday' ? 1 : 4
+
+    return [...Array(7).keys()]
+        .map((day) => format(new Date(Date.UTC(year, month, day))))
+}
+
+export function getFirstDayInMonth(month = 0, year = 2025) {
+    if (month === -1) {
+        month = 11
+        year--
+    }
+    if (month === 12) {
+        month = 0
+        year++
+    }
+    return new Date(year, month, 1).getDay()
+}
+
+export function getDaysInMonth(month = 0, year = 2025) {
+    month++
+    if (month === -1) {
+        month = 11
+        year--
+    }
+    if (month === 12) {
+        month = 0
+        year++
+    }
+
+    return new Date(year, month, 0).getDate()
+}