diff --git a/docs/en/I18n.md b/docs/en/I18n.md
index 401063aa..f1100da0 100644
--- a/docs/en/I18n.md
+++ b/docs/en/I18n.md
@@ -92,6 +92,7 @@ const localeObject = {
   weekdaysShort: 'Sun_M'.split('_'), // OPTIONAL, short weekdays Array, use first three letters if not provided
   weekdaysMin: 'Su_Mo'.split('_'), // OPTIONAL, min weekdays Array, use first two letters if not provided
   weekStart: 1, // OPTIONAL, set the start of a week. If the value is 1, Monday will be the start of week instead of Sunday。
+  yearStart: 4, // OPTIONAL, the week that contains Jan 4th is the first week of the year.
   months: 'Enero_Febrero ... '.split('_'), // months Array
   monthsShort: 'Jan_F'.split('_'), // OPTIONAL, short months Array, use first three letters if not provided
   ordinal: n => `${n}º`, // ordinal Function (number) => return number + output
diff --git a/docs/es-es/I18n.md b/docs/es-es/I18n.md
index 98926970..839fb266 100644
--- a/docs/es-es/I18n.md
+++ b/docs/es-es/I18n.md
@@ -95,6 +95,8 @@ const localeObject = {
   weekdays: 'Domingo_Lunes ...'.split('_'), // weekdays Array
   weekdaysShort: 'Sun_M'.split('_'), // OPTIONAL, short weekdays Array, use first three letters if not provided
   weekdaysMin: 'Su_Mo'.split('_'), // OPTIONAL, min weekdays Array, use first two letters if not provided
+  weekStart: 1, // OPTIONAL, set the start of a week. If the value is 1, Monday will be the start of week instead of Sunday。
+  yearStart: 4, // OPTIONAL, the week that contains Jan 4th is the first week of the year.
   months: 'Enero_Febrero ... '.split('_'), // months Array
   monthsShort: 'Jan_F'.split('_'), // OPTIONAL, short months Array, use first three letters if not provided
   ordinal: n => `${n}º`, // ordinal Function (number) => return number + output
diff --git a/docs/ja/I18n.md b/docs/ja/I18n.md
index a0dab94f..1fb090b7 100644
--- a/docs/ja/I18n.md
+++ b/docs/ja/I18n.md
@@ -92,6 +92,7 @@ const localeObject = {
   weekdaysShort: 'Sun_M'.split('_'), // OPTIONAL, short weekdays Array, use first three letters if not provided
   weekdaysMin: 'Su_Mo'.split('_'), // OPTIONAL, min weekdays Array, use first two letters if not provided
   weekStart: 1, // OPTIONAL, 最初の曜日を指定する。０は日曜日です。１は月曜日です。
+  yearStart: 4, // OPTIONAL, the week that contains Jan 4th is the first week of the year.
   months: 'Enero_Febrero ... '.split('_'), // 月の配列
   monthsShort: 'Jan_F'.split('_'), // OPTIONAL, short months Array, use first three letters if not provided
   ordinal: n => `${n}º`, // 序数 Function (number) => return number + output
diff --git a/docs/ko/I18n.md b/docs/ko/I18n.md
index 5df968cd..e7d73320 100644
--- a/docs/ko/I18n.md
+++ b/docs/ko/I18n.md
@@ -92,6 +92,7 @@ const localeObject = {
   weekdaysShort: 'Sun_M'.split('_'), // OPTIONAL, short weekdays Array, use first three letters if not provided
   weekdaysMin: 'Su_Mo'.split('_'), // OPTIONAL, min weekdays Array, use first two letters if not provided
   weekStart: 1, // OPTIONAL, set the start of a week. If the value is 1, Monday will be the start of week instead of Sunday。
+  yearStart: 4, // OPTIONAL, the week that contains Jan 4th is the first week of the year.
   months: 'Enero_Febrero ... '.split('_'), // months Array
   monthsShort: 'Jan_F'.split('_'), // OPTIONAL, short months Array, use first three letters if not provided
   ordinal: n => `${n}º`, // ordinal Function (number) => return number + output
diff --git a/docs/pt-br/I18n.md b/docs/pt-br/I18n.md
index 4a383ecf..18fef9b5 100644
--- a/docs/pt-br/I18n.md
+++ b/docs/pt-br/I18n.md
@@ -92,6 +92,7 @@ const objetoLocale = {
   weekdaysShort: 'Sun_M'.split('_'), // OPCIONAL, dias da semana com nome curto: Array, utiliza as três primeiras letras se nenhuma for especificada
   weekdaysMin: 'Su_Mo'.split('_'), // OPCIONAL, dias da semana com nome mínimo: Array, utiliza as duas primeiras letras se nenhuma for especificada
   weekStart: 1, // OPCIONAL, define o início da semana. Se o valor for 1, Segunda-feira será o início da semana ao invés de Domingo。
+  yearStart: 4, // OPTIONAL, the week that contains Jan 4th is the first week of the year.
   months: 'Enero_Febrero ... '.split('_'), // meses: Array
   monthsShort: 'Jan_F'.split('_'), // OPCIONAL, meses com nome curto: Array, utiliza as três primeiras letras se nenhuma for especificada
   ordinal: n => `${n}º`, // ordinal: Function (number) => retorna number + saída
diff --git a/docs/zh-cn/I18n.md b/docs/zh-cn/I18n.md
index 55b4aa10..29e1875b 100644
--- a/docs/zh-cn/I18n.md
+++ b/docs/zh-cn/I18n.md
@@ -92,6 +92,7 @@ const localeObject = {
   weekdaysShort: 'Sun_M'.split('_'), // 可选, 短的星期 Array, 如果没提供则使用前三个字符
   weekdaysMin: 'Su_Mo'.split('_'), // 可选, 最短的星期 Array, 如果没提供则使用前两个字符
   weekStart: 1, // 可选，指定一周的第一天。默认为0，即周日。如果为1，则周一为一周得第一天。
+  yearStart: 4, // 可选，包含1月4日的周为一年的第一周
   months: 'Enero_Febrero ... '.split('_'), // 月份 Array
   monthsShort: 'Jan_F'.split('_'), // 可选, 短的月份 Array, 如果没提供则使用前三个字符
   ordinal: n => `${n}º`, // 序号生成工厂函数 Function (number) => return number + output
diff --git a/src/locale/en-gb.js b/src/locale/en-gb.js
index dfa84d2c..d8cf7e10 100644
--- a/src/locale/en-gb.js
+++ b/src/locale/en-gb.js
@@ -8,6 +8,7 @@ const locale = {
   months: 'January_February_March_April_May_June_July_August_September_October_November_December'.split('_'),
   monthsShort: 'Jan_Feb_Mar_Apr_May_Jun_Jul_Aug_Sep_Oct_Nov_Dec'.split('_'),
   weekStart: 1,
+  yearStart: 4,
   relativeTime: {
     future: 'in %s',
     past: '%s ago',
diff --git a/src/locale/zh-cn.js b/src/locale/zh-cn.js
index f1595175..774c6304 100644
--- a/src/locale/zh-cn.js
+++ b/src/locale/zh-cn.js
@@ -16,6 +16,7 @@ const locale = {
     }
   },
   weekStart: 1,
+  yearStart: 4,
   formats: {
     LT: 'HH:mm',
     LTS: 'HH:mm:ss',
diff --git a/src/plugin/weekOfYear/index.js b/src/plugin/weekOfYear/index.js
index 7251d5af..f0c6088d 100644
--- a/src/plugin/weekOfYear/index.js
+++ b/src/plugin/weekOfYear/index.js
@@ -1,17 +1,26 @@
 import { MS, Y, D, W } from '../../constant'
 
-export default (o, c, d) => {
+export default (o, c) => {
   const proto = c.prototype
   proto.week = function (week = null) {
     if (week !== null) {
-      return this.add((week - this.week()) * 7, 'day')
+      return this.add((week - this.week()) * 7, D)
     }
-    const weekStart = this.$locale().weekStart || 0
-    const startOfYear = d(this).startOf(Y)
-    const compareDay = startOfYear.subtract(startOfYear.day() - weekStart, D).subtract(1, MS)
-    const diffInWeek = this.diff(compareDay, W, true)
-    const result = Math.ceil(diffInWeek)
-    return result > 52 ? 1 : result
+    const yearStart = this.$locale().yearStart || 1
+    if (this.month() === 11 && this.date() > 25) {
+      const nextYearStartDay = this.startOf(Y).add(1, Y).date(yearStart)
+      const thisEndOfWeek = this.endOf(W)
+      if (nextYearStartDay.isBefore(thisEndOfWeek)) {
+        return 1
+      }
+    }
+    const yearStartDay = this.startOf(Y).date(yearStart)
+    const yearStartWeek = yearStartDay.startOf(W).subtract(1, MS)
+    const diffInWeek = this.diff(yearStartWeek, W, true)
+    if (diffInWeek < 0) {
+      return this.startOf('week').week()
+    }
+    return Math.ceil(diffInWeek)
   }
 
   proto.weeks = function (week = null) {
diff --git a/test/locale/keys.test.js b/test/locale/keys.test.js
index a06960a3..5def0014 100644
--- a/test/locale/keys.test.js
+++ b/test/locale/keys.test.js
@@ -28,6 +28,7 @@ Locale.forEach((locale) => {
       monthsShort,
       weekdaysMin,
       weekStart,
+      yearStart,
       meridiem
     } = locale.content
 
@@ -37,6 +38,7 @@ Locale.forEach((locale) => {
     if (weekdaysShort) expect(weekdaysShort).toEqual(expect.any(Array))
     if (weekdaysMin) expect(weekdaysMin).toEqual(expect.any(Array))
     if (weekStart) expect(weekStart).toEqual(expect.any(Number))
+    if (yearStart) expect(yearStart).toEqual(expect.any(Number))
 
     // months could be a function or array
     if (Array.isArray(months)) {
diff --git a/test/plugin/weekOfYear.test.js b/test/plugin/weekOfYear.test.js
index 980b4bc7..576b0c78 100644
--- a/test/plugin/weekOfYear.test.js
+++ b/test/plugin/weekOfYear.test.js
@@ -33,14 +33,25 @@ it('Week of year', () => {
 it('Week of year with locale', () => {
   dayjs.locale('en-gb')
   moment.locale('en-gb')
-
   const day = '2019-07-28'
   expect(dayjs(day).week()).toBe(moment(day).week())
+})
 
-  // Edges
-  expect(dayjs('2018-12-30').week()).toBe(moment('2018-12-30').week())
-  expect(dayjs('2019-12-29').week()).toBe(moment('2019-12-29').week())
-  expect(dayjs('2019-12-30').week()).toBe(moment('2019-12-30').week())
+describe('Week of year with locale edges', () => {
+  const testCases = [
+    '2018-12-30',
+    '2018-12-31',
+    '2019-12-29',
+    '2019-12-30',
+    '2016-01-01',
+    '2016-01-04'
+  ]
+  testCases.forEach((t) => {
+    it(`Edges ${t}`, () => {
+      expect(dayjs(t).week())
+        .toBe(moment(t).week())
+    })
+  })
 })
 
 it('Format w ww wo', () => {
diff --git a/test/plugin/weekday.test.js b/test/plugin/weekday.test.js
index 703f3ec8..52b7a938 100644
--- a/test/plugin/weekday.test.js
+++ b/test/plugin/weekday.test.js
@@ -31,6 +31,10 @@ it('Monday is the first day of the week', () => {
   expect(dayjs().weekday(0).date()).toBe(moment().weekday(0).date())
   expect(dayjs().weekday(-7).format()).toBe(moment().weekday(-7).format())
   expect(dayjs().weekday(7).format()).toBe(moment().weekday(7).format())
+  const d1 = '2020-01-05'
+  expect(dayjs(d1).weekday()).toBe(moment(d1).weekday())
+  const d2 = '2020-01-07'
+  expect(dayjs(d2).weekday()).toBe(moment(d2).weekday())
 })
 
 it('Saturday is the first day of the week', () => {