chore: optimize experience of hover value

examples/basic.tsx

@@ -1,5 +1,6 @@
 import React from 'react';
-import moment, { Moment } from 'moment';
+import type { Moment } from 'moment';
+import moment from 'moment';
 import Picker from '../src/Picker';
 import momentGenerateConfig from '../src/generate/moment';
 import zhCN from '../src/locale/zh_CN';

src/PickerPanel.tsx

@@ -37,7 +37,7 @@ import type { MonthCellRender } from './panels/MonthPanel/MonthBody';
 import RangeContext from './RangeContext';
 import getExtraFooter from './utils/getExtraFooter';
 import getRanges from './utils/getRanges';
-import { getLowerBoundTime, setTime } from './utils/timeUtil';
+import { getLowerBoundTime, setDateTime, setTime } from './utils/timeUtil';
 
 export type PickerPanelSharedProps<DateType> = {
   prefixCls?: string;
@@ -202,7 +202,21 @@ function PickerPanel<DateType>(props: PickerPanelProps<DateType>) {
   const [viewDate, setInnerViewDate] = useMergedState<DateType | null, DateType>(null, {
     value: pickerValue,
     defaultValue: defaultPickerValue || mergedValue,
-    postState: (date) => date || generateConfig.getNow(),
+    postState: (date) => {
+      const now = generateConfig.getNow();
+      if (!date) return now;
+      // When value is null and set showTime
+      if (!mergedValue && showTime) {
+        if (typeof showTime === 'object') {
+          return setDateTime(generateConfig, date, showTime.defaultValue || now);
+        }
+        if (defaultValue) {
+          return setDateTime(generateConfig, date, defaultValue);
+        }
+        return setDateTime(generateConfig, date, now);
+      }
+      return date;
+    },
   });
 
   const setViewDate = (date: DateType) => {

src/panels/DatetimePanel/index.tsx

@@ -6,33 +6,8 @@ import DatePanel from '../DatePanel';
 import type { SharedTimeProps } from '../TimePanel';
 import TimePanel from '../TimePanel';
 import { tuple } from '../../utils/miscUtil';
-import type { PanelRefProps, DisabledTime, NullableDateType } from '../../interface';
-import type { GenerateConfig } from '../../generate';
-
-function setTime<DateType>(
-  generateConfig: GenerateConfig<DateType>,
-  date: DateType,
-  defaultDate: NullableDateType<DateType>,
-) {
-  if (!defaultDate) {
-    return date;
-  }
-
-  let newDate = date;
-  newDate = generateConfig.setHour(
-    newDate,
-    generateConfig.getHour(defaultDate),
-  );
-  newDate = generateConfig.setMinute(
-    newDate,
-    generateConfig.getMinute(defaultDate),
-  );
-  newDate = generateConfig.setSecond(
-    newDate,
-    generateConfig.getSecond(defaultDate),
-  );
-  return newDate;
-}
+import { setDateTime as setTime } from '../../utils/timeUtil';
+import type { PanelRefProps, DisabledTime } from '../../interface';
 
 export type DatetimePanelProps<DateType> = {
   disabledTime?: DisabledTime<DateType>;

src/utils/timeUtil.ts

@@ -1,3 +1,4 @@
+import type { NullableDateType } from '../interface';
 import type { GenerateConfig } from '../generate';
 
 export function setTime<DateType>(
@@ -13,6 +14,32 @@ export function setTime<DateType>(
   return nextTime;
 }
 
+export function setDateTime<DateType>(
+  generateConfig: GenerateConfig<DateType>,
+  date: DateType,
+  defaultDate: NullableDateType<DateType>,
+) {
+  if (!defaultDate) {
+    return date;
+  }
+
+  let newDate = date;
+  newDate = generateConfig.setHour(
+    newDate,
+    generateConfig.getHour(defaultDate),
+  );
+  newDate = generateConfig.setMinute(
+    newDate,
+    generateConfig.getMinute(defaultDate),
+  );
+  newDate = generateConfig.setSecond(
+    newDate,
+    generateConfig.getSecond(defaultDate),
+  );
+  return newDate;
+}
+
+
 export function getLowerBoundTime(
   hour: number,
   minute: number,