[improvement] DatetimePicker: jsx (#2510)

packages/datetime-picker/utils.js

@@ -0,0 +1,29 @@
+export function isValidDate(date) {
+  return Object.prototype.toString.call(date) === '[object Date]' && !isNaN(date.getTime());
+}
+
+export function padZero(val) {
+  return `00${val}`.slice(-2);
+}
+
+export function times(n, iteratee) {
+  let index = -1;
+  const result = Array(n);
+
+  while (++index < n) {
+    result[index] = iteratee(index);
+  }
+  return result;
+}
+
+export function getTrueValue(formattedValue) {
+  if (!formattedValue) return;
+  while (isNaN(parseInt(formattedValue, 10))) {
+    formattedValue = formattedValue.slice(1);
+  }
+  return parseInt(formattedValue, 10);
+}
+
+export function getMonthEndDay(year, month) {
+  return 32 - new Date(year, month - 1, 32).getDate();
+}