diff --git a/README.md b/README.md
index 92001ce7a..1ed2ecd88 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,8 @@
 [![Coverage Status](https://img.shields.io/codecov/c/github/youzan/vant/dev.svg)](https://codecov.io/github/youzan/vant?branch=dev)
 [![npm version](https://img.shields.io/npm/v/vant.svg?style=flat)](https://www.npmjs.com/package/vant)
 [![license](https://img.shields.io/npm/l/vant.svg)](https://www.npmjs.com/package/vant)
+[![JS Gzip Size](http://img.badgesize.io/https://unpkg.com/vant/lib/vant.min.js?compression=gzip&style=flat-square&label=JS%20gzip%20size)](https://unpkg.com/vant/lib/vant.min.js)
+[![CSS Gzip Size](http://img.badgesize.io/https://unpkg.com/vant/lib/vant-css/index.css?compression=gzip&style=flat-square&label=CSS%20gzip%20size)](https://unpkg.com/vant/lib/vant-css/index.css)
 
 [访问中文版](./README.zh-CN.md)
 
diff --git a/README.zh-CN.md b/README.zh-CN.md
index f62ee0379..ae04680a6 100644
--- a/README.zh-CN.md
+++ b/README.zh-CN.md
@@ -12,6 +12,8 @@
 [![Coverage Status](https://img.shields.io/codecov/c/github/youzan/vant/dev.svg)](https://codecov.io/github/youzan/vant?branch=dev)
 [![npm version](https://img.shields.io/npm/v/vant.svg?style=flat)](https://www.npmjs.com/package/vant)
 [![license](https://img.shields.io/npm/l/vant.svg)](https://www.npmjs.com/package/vant)
+[![JS Gzip Size](http://img.badgesize.io/https://unpkg.com/vant/lib/vant.min.js?compression=gzip&style=flat-square&label=JS%20gzip%20size)](https://unpkg.com/vant/lib/vant.min.js)
+[![CSS Gzip Size](http://img.badgesize.io/https://unpkg.com/vant/lib/vant-css/index.css?compression=gzip&style=flat-square&label=CSS%20gzip%20size)](https://unpkg.com/vant/lib/vant-css/index.css)
 
 ## 特性
 
diff --git a/packages/datetime-picker/index.vue b/packages/datetime-picker/index.vue
index 275b1ba43..203bbfa25 100644
--- a/packages/datetime-picker/index.vue
+++ b/packages/datetime-picker/index.vue
@@ -223,7 +223,7 @@ export default create({
     },
 
     isLeapYear(year) {
-      return (year % 400 === 0) || (year % 100 !== 0 && year % 4 === 0);
+      return (year % 4 === 0 && year % 100 !== 0) || (year % 400 === 0);
     },
 
     isShortMonth(month) {