fix(components): [date-picker] selected value comparison logic error (#15918)

* fix(components): [date-picker] selected value comparison logic error

* test(components): [date-picker] selected value comparison logic error

* perf(components): [date-picker] selected value comparison logic error

Co-authored-by: kooriookami <38392315+kooriookami@users.noreply.github.com>

---------

Co-authored-by: kooriookami <38392315+kooriookami@users.noreply.github.com>

packages/components/date-picker/__tests__/date-picker.test.ts

@@ -1006,6 +1006,23 @@ describe('DatePicker dates', () => {
     await nextTick()
     expect(vm.value.length).toBe(0)
   })
+
+  it('selected', async () => {
+    const wrapper = _mount(
+      `<el-date-picker
+        type="dates"
+        v-model="value"
+      />`,
+      () => ({ value: [new Date()] })
+    )
+    const input = wrapper.find('input')
+    input.trigger('blur')
+    input.trigger('focus')
+    await nextTick()
+    expect(
+      document.querySelectorAll('.el-date-table__row .selected').length
+    ).toBe(1)
+  })
 })
 
 describe('DatePicker keyboard events', () => {

packages/components/date-picker/src/composables/use-basic-date-table.ts

@@ -133,9 +133,7 @@ export const useBasicDateTable = (
     const shouldIncrement = setDateText(cell, { count, rowIndex, columnIndex })
 
     const cellDate = cell.dayjs!.toDate()
-    cell.selected = _selectedDate.find(
-      (d) => d.valueOf() === cell.dayjs!.valueOf()
-    )
+    cell.selected = _selectedDate.find((d) => d.isSame(cell.dayjs, 'day'))
     cell.isSelected = !!cell.selected
     cell.isCurrent = isCurrent(cell)
     cell.disabled = disabledDate?.(cellDate)