function to compose 42 calendar days based on given date was created

packages/components/calendar/utils/getCalendarDays.js

@@ -0,0 +1,46 @@
+import moment from "moment";
+
+export const getCalendarDays = (date) => {
+  const selectedDate = moment(date);
+
+  const prevMonthDays = [];
+  const currentMonthDays = [];
+  const nextMonthDays = [];
+  const maxCalendarDays = 42;
+
+  const monthFirstMonday = selectedDate.clone().startOf("month").weekday(1).date();
+  const firstCalendarMonday =
+    monthFirstMonday < 10
+      ? selectedDate.clone().startOf("month").subtract(1, "week").weekday(1).date()
+      : monthFirstMonday;
+
+  for (let i = 1; i <= selectedDate.clone().daysInMonth(); i++) {
+    currentMonthDays.push({
+      key: selectedDate.clone().format("YYYY-MM") + "-" + i,
+      value: i,
+    });
+  }
+
+  if (monthFirstMonday !== 1) {
+    const prevMonthLength = selectedDate.clone().subtract(1, "months").daysInMonth();
+    for (let i = firstCalendarMonday; i <= prevMonthLength; i++) {
+      prevMonthDays.push({
+        key: selectedDate.clone().subtract(1, "months").format("YYYY-MM") + "-" + i,
+        value: i,
+      });
+    }
+  }
+
+  for (
+    let i = 1;
+    i <= maxCalendarDays - currentMonthDays.length - prevMonthDays.length;
+    i++
+  ) {
+    nextMonthDays.push({
+      key: selectedDate.clone().add(1, "months").format("YYYY-MM") + "-" + i,
+      value: i,
+    });
+  }
+
+  return { prevMonthDays, currentMonthDays, nextMonthDays };
+};