diff --git a/aio/content/translations/cn/api-plan.md b/aio/content/translations/cn/api-plan.md
index 5c0e9f6ebe..5f79a2432e 100644
--- a/aio/content/translations/cn/api-plan.md
+++ b/aio/content/translations/cn/api-plan.md
@@ -13,7 +13,7 @@
[x] |router/Router | 4,049 | 1.26
[ ] |animations/animate | 3,817 | 1.19
[x] |common/NgClass | 3,715 | 1.15
-[ ] |common/DatePipe | 3,576 | 1.11
+[x] |common/DatePipe | 3,576 | 1.11
[ ] |forms/FormsModule | 3,381 | 1.05
[x] |core/Input | 3,354 | 1.04
[x] |core/EventEmitter | 3,202 | 0.99
diff --git a/packages/common/src/pipes/date_pipe.ts b/packages/common/src/pipes/date_pipe.ts
index c0365c42b5..ede7d40ebe 100644
--- a/packages/common/src/pipes/date_pipe.ts
+++ b/packages/common/src/pipes/date_pipe.ts
@@ -17,10 +17,15 @@ import {invalidPipeArgumentError} from './invalid_pipe_argument_error';
*
* Formats a date value according to locale rules.
*
+ * 根据区域设置规则格式化日期值。
+ *
* Only the `en-US` locale data comes with Angular. To localize dates
* in another language, you must import the corresponding locale data.
* See the [I18n guide](guide/i18n#i18n-pipes) for more information.
*
+ * Angular 只自带了 `en-US` 区域的数据。要想在其它语言中对日期进行本地化，你必须导入相应的区域数据。
+ * 欲知详情，参见 [I18n guide](guide/i18n#i18n-pipes)。
+ *
* @see `formatDate()`
*
*
@@ -30,97 +35,154 @@ import {invalidPipeArgumentError} from './invalid_pipe_argument_error';
* reformat the date on every change-detection cycle, treat the date as an immutable object
* and change the reference when the pipe needs to run again.
*
+ * 当输入值发生变化时，该管道的结果并不会改变。如果不想在每个变更检测周期中都强制重新格式化该日期，请把日期看做一个不可变对象，
+ * 当需要让该管道重新运行时，请赋给它一个新的对象，以更改它的引用。
+ *
* ### Pre-defined format options
*
+ * ### 预定义的格式选项
+ *
* Examples are given in `en-US` locale.
*
+ * 下面是 `en-US` 区域的例子。
+ *
* - `'short'`: equivalent to `'M/d/yy, h:mm a'` (`6/15/15, 9:03 AM`).
+ *
+ * `'short'`: 等价于 `'M/d/yy, h:mm a'` (`6/15/15, 9:03 AM`).
+ *
* - `'medium'`: equivalent to `'MMM d, y, h:mm:ss a'` (`Jun 15, 2015, 9:03:01 AM`).
+ *
+ * `'medium'`: 等价于 `'MMM d, y, h:mm:ss a'` (`Jun 15, 2015, 9:03:01 AM`).
+ *
* - `'long'`: equivalent to `'MMMM d, y, h:mm:ss a z'` (`June 15, 2015 at 9:03:01 AM
+ *
+ * `'long'`: 等价于 `'MMMM d, y, h:mm:ss a z'` (`June 15, 2015 at 9:03:01 AM
+ *
* GMT+1`).
* - `'full'`: equivalent to `'EEEE, MMMM d, y, h:mm:ss a zzzz'` (`Monday, June 15, 2015 at
+ *
+ * `'full'`: 等价于 `'EEEE, MMMM d, y, h:mm:ss a zzzz'` (`Monday, June 15, 2015 at
+ *
* 9:03:01 AM GMT+01:00`).
* - `'shortDate'`: equivalent to `'M/d/yy'` (`6/15/15`).
+ *
+ * `'shortDate'`: 等价于 `'M/d/yy'` (`6/15/15`).
+ *
* - `'mediumDate'`: equivalent to `'MMM d, y'` (`Jun 15, 2015`).
+ *
+ * `'mediumDate'`: 等价于 `'MMM d, y'` (`Jun 15, 2015`).
+ *
* - `'longDate'`: equivalent to `'MMMM d, y'` (`June 15, 2015`).
+ *
+ * `'longDate'`: 等价于 `'MMMM d, y'` (`June 15, 2015`).
+ *
* - `'fullDate'`: equivalent to `'EEEE, MMMM d, y'` (`Monday, June 15, 2015`).
+ *
+ * `'fullDate'`: 等价于 `'EEEE, MMMM d, y'` (`Monday, June 15, 2015`).
+ *
* - `'shortTime'`: equivalent to `'h:mm a'` (`9:03 AM`).
+ *
+ * `'shortTime'`: 等价于 `'h:mm a'` (`9:03 AM`).
+ *
* - `'mediumTime'`: equivalent to `'h:mm:ss a'` (`9:03:01 AM`).
+ *
+ * `'mediumTime'`: 等价于 `'h:mm:ss a'` (`9:03:01 AM`).
+ *
* - `'longTime'`: equivalent to `'h:mm:ss a z'` (`9:03:01 AM GMT+1`).
+ *
+ * `'longTime'`: 等价于 `'h:mm:ss a z'` (`9:03:01 AM GMT+1`).
+ *
* - `'fullTime'`: equivalent to `'h:mm:ss a zzzz'` (`9:03:01 AM GMT+01:00`).
*
+ * `'fullTime'`: 等价于 `'h:mm:ss a zzzz'` (`9:03:01 AM GMT+01:00`).
+ *
+ *
* ### Custom format options
*
+ * ### 自定义格式选项
+ *
* You can construct a format string using symbols to specify the components
* of a date-time value, as described in the following table.
* Format details depend on the locale.
* Fields marked with (*) are only available in the extra data set for the given locale.
*
- * | Field type | Format | Description | Example Value |
+ * 你可以使用符号来构造出格式字符串，以指定日期-时间值的各个部分，如下表所示。
+ * 具体格式取决于区域设置。
+ * 标 `*` 的字段表示仅在特定区域的数据中才有效。
+ *
+ * | Field type字段类型 | Format格式 | Description说明 | Example Value范例值 |
* |--------------------|-------------|---------------------------------------------------------------|------------------------------------------------------------|
- * | Era | G, GG & GGG | Abbreviated | AD |
- * | | GGGG | Wide | Anno Domini |
- * | | GGGGG | Narrow | A |
- * | Year | y | Numeric: minimum digits | 2, 20, 201, 2017, 20173 |
- * | | yy | Numeric: 2 digits + zero padded | 02, 20, 01, 17, 73 |
- * | | yyy | Numeric: 3 digits + zero padded | 002, 020, 201, 2017, 20173 |
- * | | yyyy | Numeric: 4 digits or more + zero padded | 0002, 0020, 0201, 2017, 20173 |
- * | Month | M | Numeric: 1 digit | 9, 12 |
- * | | MM | Numeric: 2 digits + zero padded | 09, 12 |
- * | | MMM | Abbreviated | Sep |
- * | | MMMM | Wide | September |
- * | | MMMMM | Narrow | S |
- * | Month standalone | L | Numeric: 1 digit | 9, 12 |
- * | | LL | Numeric: 2 digits + zero padded | 09, 12 |
- * | | LLL | Abbreviated | Sep |
- * | | LLLL | Wide | September |
- * | | LLLLL | Narrow | S |
- * | Week of year | w | Numeric: minimum digits | 1... 53 |
- * | | ww | Numeric: 2 digits + zero padded | 01... 53 |
- * | Week of month | W | Numeric: 1 digit | 1... 5 |
- * | Day of month | d | Numeric: minimum digits | 1 |
- * | | dd | Numeric: 2 digits + zero padded | 01 |
- * | Week day | E, EE & EEE | Abbreviated | Tue |
- * | | EEEE | Wide | Tuesday |
- * | | EEEEE | Narrow | T |
- * | | EEEEEE | Short | Tu |
- * | Period | a, aa & aaa | Abbreviated | am/pm or AM/PM |
- * | | aaaa | Wide (fallback to `a` when missing) | ante meridiem/post meridiem |
- * | | aaaaa | Narrow | a/p |
- * | Period* | B, BB & BBB | Abbreviated | mid. |
- * | | BBBB | Wide | am, pm, midnight, noon, morning, afternoon, evening, night |
- * | | BBBBB | Narrow | md |
- * | Period standalone* | b, bb & bbb | Abbreviated | mid. |
- * | | bbbb | Wide | am, pm, midnight, noon, morning, afternoon, evening, night |
- * | | bbbbb | Narrow | md |
- * | Hour 1-12 | h | Numeric: minimum digits | 1, 12 |
- * | | hh | Numeric: 2 digits + zero padded | 01, 12 |
- * | Hour 0-23 | H | Numeric: minimum digits | 0, 23 |
- * | | HH | Numeric: 2 digits + zero padded | 00, 23 |
- * | Minute | m | Numeric: minimum digits | 8, 59 |
- * | | mm | Numeric: 2 digits + zero padded | 08, 59 |
- * | Second | s | Numeric: minimum digits | 0... 59 |
- * | | ss | Numeric: 2 digits + zero padded | 00... 59 |
- * | Fractional seconds | S | Numeric: 1 digit | 0... 9 |
- * | | SS | Numeric: 2 digits + zero padded | 00... 99 |
- * | | SSS | Numeric: 3 digits + zero padded (= milliseconds) | 000... 999 |
- * | Zone | z, zz & zzz | Short specific non location format (fallback to O) | GMT-8 |
- * | | zzzz | Long specific non location format (fallback to OOOO) | GMT-08:00 |
- * | | Z, ZZ & ZZZ | ISO8601 basic format | -0800 |
- * | | ZZZZ | Long localized GMT format | GMT-8:00 |
- * | | ZZZZZ | ISO8601 extended format + Z indicator for offset 0 (= XXXXX) | -08:00 |
- * | | O, OO & OOO | Short localized GMT format | GMT-8 |
- * | | OOOO | Long localized GMT format | GMT-08:00 |
+ * | Era纪元 | G, GG & GGG | Abbreviated缩略| AD |
+ * | | GGGG | Wide全称| Anno Domini |
+ * | | GGGGG | Narrow最简| A |
+ * | Year年 | y | Numeric数字: minimum digits最小位数 | 2, 20, 201, 2017, 20173 |
+ * | | yy | Numeric数字: 2 digits + zero padded数字 + 0 补位 | 02, 20, 01, 17, 73 |
+ * | | yyy | Numeric数字: 3 digits + zero padded数字 + 0 补位 | 002, 020, 201, 2017, 20173 |
+ * | | yyyy | Numeric数字: 4 digits or more + zero padded或更多数字 + 0 补位 | 0002, 0020, 0201, 2017, 20173 |
+ * | Month月 | M | Numeric数字: 1 digit1 数字 | 9, 12 |
+ * | | MM | Numeric数字: 2 digits + zero padded数字 + 0 补位 | 09, 12 |
+ * | | MMM | Abbreviated缩略| Sep |
+ * | | MMMM | Wide全称| September |
+ * | | MMMMM | Narrow最简| S |
+ * | Month standalone独立月份 | L | Numeric数字: 1 digit1 数字 | 9, 12 |
+ * | | LL | Numeric数字: 2 digits + zero padded数字 + 0 补位 | 09, 12 |
+ * | | LLL | Abbreviated缩略| Sep |
+ * | | LLLL | Wide全称| September |
+ * | | LLLLL | Narrow最简| S |
+ * | Week of year年内周次 | w | Numeric数字: minimum digits最小位数 | 1... 53 |
+ * | | ww | Numeric数字: 2 digits + zero padded数字 + 0 补位 | 01... 53 |
+ * | Week of month月内周次 | W | Numeric数字: 1 digit1 数字 | 1... 5 |
+ * | Day of month月内日 | d | Numeric数字: minimum digits最小位数 | 1 |
+ * | | dd | Numeric数字: 2 digits + zero padded数字 + 0 补位 | 01 |
+ * | Week day周内日 | E, EE & EEE | Abbreviated缩略| Tue |
+ * | | EEEE | Wide全称| Tuesday |
+ * | | EEEEE | Narrow最简| T |
+ * | | EEEEEE | Short短 | Tu |
+ * | Period日内时段 | a, aa & aaa | Abbreviated缩略| am/pm or AM/PM |
+ * | | aaaa | Wide全称(fallback to `a` when missing)(缺少时等同于 `a`)| ante meridiem/post meridiem |
+ * | | aaaaa | Narrow最简| a/p |
+ * | Period*日内时段 | B, BB & BBB | Abbreviated缩略| mid. |
+ * | | BBBB | Wide全称| am, pm, midnight, noon, morning, afternoon, evening, night |
+ * | | BBBBB | Narrow最简| md |
+ * | Period standalone*独立时段 | b, bb & bbb | Abbreviated缩略| mid. |
+ * | | bbbb | Wide全称| am, pm, midnight, noon, morning, afternoon, evening, night |
+ * | | bbbbb | Narrow最简| md |
+ * | Hour 1-12小时(1-12) | h | Numeric数字: minimum digits最小位数 | 1, 12 |
+ * | | hh | Numeric数字: 2 digits + zero padded数字 + 0 补位 | 01, 12 |
+ * | Hour 0-23小时(0-23) | H | Numeric数字: minimum digits最小位数 | 0, 23 |
+ * | | HH | Numeric数字: 2 digits + zero padded数字 + 0 补位 | 00, 23 |
+ * | Minute分 | m | Numeric数字: minimum digits最小位数 | 8, 59 |
+ * | | mm | Numeric数字: 2 digits + zero padded数字 + 0 补位 | 08, 59 |
+ * | Second秒 | s | Numeric数字: minimum digits最小位数 | 0... 59 |
+ * | | ss | Numeric数字: 2 digits + zero padded数字 + 0 补位 | 00... 59 |
+ * | Fractional seconds分数秒 | S | Numeric数字: 1 digit1 数字 | 0... 9 |
+ * | | SS | Numeric数字: 2 digits + zero padded数字 + 0 补位 | 00... 99 |
+ * | | SSS | Numeric数字: 3 digits + zero padded数字 + 0 补位 (= milliseconds毫秒) | 000... 999 |
+ * | Zone时区 | z, zz & zzz | Short specific non location format (fallback to O)位置无关短格式（默认为0） | GMT-8 |
+ * | | zzzz | Long specific non location format (fallback to OOOO)位置无关长格式（默认为0000） | GMT-08:00 |
+ * | | Z, ZZ & ZZZ | ISO8601 basic format基本格式 | -0800 |
+ * | | ZZZZ | Long localized GMT format本地化 GMT 长格式 | GMT-8:00 |
+ * | | ZZZZZ | ISO8601 extended format + Z indicator for offset 0扩展格式 + 偏移为 0 时用 Z 表示 (= XXXXX) | -08:00 |
+ * | | O, OO & OOO | Short localized GMT format本地化 GMT 短格式 | GMT-8 |
+ * | | OOOO | Long localized GMT format本地化 GMT 长格式 | GMT-08:00 |
*
* Note that timezone correction is not applied to an ISO string that has no time component, such as "2016-09-19"
*
+ * 请注意，时区校正不适用于没有时间部分的ISO字符串，例如“2016-09-19”
+ *
* ### Format examples
*
+ * ### 格式范例
+ *
* These examples transform a date into various formats,
* assuming that `dateObj` is a JavaScript `Date` object for
* year: 2015, month: 6, day: 15, hour: 21, minute: 43, second: 11,
* given in the local time for the `en-US` locale.
*
+ * 下面这些例子会把日期转换成多种格式。
+ * 这里假设 `dateObj` 是个 JavaScript 的 `Date` 对象： 2015 年 6 月 15 日 21 时 43 分 11 秒，
+ * 使用的是 `en-US` 区域的当地时间。
+ *
* ```
* {{ dateObj | date }} // output is 'Jun 15, 2015'
* {{ dateObj | date:'medium' }} // output is 'Jun 15, 2015, 9:43:11 PM'
@@ -130,8 +192,12 @@ import {invalidPipeArgumentError} from './invalid_pipe_argument_error';
*
* ### Usage example
*
+ * ### 使用范例
+ *
* The following component uses a date pipe to display the current date in different formats.
*
+ * 下列组件借助一个日期管道来以不同的格式显示当前日期。
+ *
* ```
* @Component({
* selector: 'date-pipe',
@@ -156,15 +222,31 @@ export class DatePipe implements PipeTransform {
/**
* @param value The date expression: a `Date` object, a number
* (milliseconds since UTC epoch), or an ISO string (https://www.w3.org/TR/NOTE-datetime).
+ *
+ * 日期表达式：`Date` 对象、数字（从 UTC 时代以来的毫秒数）或一个 ISO 字符串 (https://www.w3.org/TR/NOTE-datetime)。
+ *
* @param format The date/time components to include, using predefined options or a
* custom format string.
+ *
+ * 要包含的日期、时间部分的格式，使用预定义选项或自定义格式字符串。
+ *
* @param timezone A timezone offset (such as `'+0430'`), or a standard
* UTC/GMT or continental US timezone abbreviation. Default is
* the local system timezone of the end-user's machine.
+ *
+ * 一个时区偏移（比如`'+0430'`）或标准的 UTC/GMT 或美国大陆时区的缩写。默认为最终用户机器上的本地系统时区。
+ *
* @param locale A locale code for the locale format rules to use.
* When not supplied, uses the value of `LOCALE_ID`, which is `en-US` by default.
* See [Setting your app locale](guide/i18n#setting-up-the-locale-of-your-app).
+ *
+ * 要使用的区域格式规则的区域代码。
+ * 如果不提供，就使用 `LOCALE_ID` 的值，默认为 `en-US`。
+ * 参见[设置应用的区域](guide/i18n#setting-up-the-locale-of-your-app)。
+ *
* @returns A date string in the desired format.
+ *
+ * 指定格式的日期字符串。
*/
transform(value: any, format = 'mediumDate', timezone?: string, locale?: string): string|null {
if (value == null || value === '' || value !== value) return null;