fix: countdown support dayjs value

Author: tangjinzhou

components/statistic/Countdown.tsx

@@ -14,7 +14,7 @@ function getTime(value?: countdownValueType) {
 export const countdownProps = () => {
   return {
     ...statisticProps(),
-    value: [Number, String],
+    value: [Number, String, Object] as PropType<countdownValueType>,
     format: String,
     onFinish: Function as PropType<() => void>,
     onChange: Function as PropType<(value?: countdownValueType) => void>,

components/statistic/utils.ts

@@ -2,7 +2,7 @@ import type { VNodeTypes } from 'vue';
 import padStart from 'lodash-es/padStart';
 
 export type valueType = number | string;
-export type countdownValueType = valueType | string;
+export type countdownValueType = valueType | Date;
 
 export type Formatter =
   | false