fix calendar day initial

assets/js/calendar.js

@@ -159,7 +159,17 @@ function createEmptyCalendar() {
     calendar[normalizedMonth] = {};
 
     for (let day = 1; day <= daysInMonth; day++) {
-      calendar[normalizedMonth][day] = null;
+      const currentDay = dayjs()
+        .month(normalizedMonth - 1)
+        .date(day);
+
+      const dayInitial = currentDay.format("dd")[0].toUpperCase();
+
+      calendar[normalizedMonth][day] = {
+        sessions: [],
+        full: currentDay.format("DD-MM-YYYY"),
+        initial: dayInitial,
+      };
     }
   }