diff --git a/app/menstrual-cycle.tsx b/app/menstrual-cycle.tsx
index 31f4daf..da03881 100644
--- a/app/menstrual-cycle.tsx
+++ b/app/menstrual-cycle.tsx
@@ -1,8 +1,8 @@
-import { Ionicons } from '@expo/vector-icons';
 import dayjs from 'dayjs';
 import { LinearGradient } from 'expo-linear-gradient';
 import { Stack, useRouter } from 'expo-router';
 import React, { useEffect, useMemo, useRef, useState } from 'react';
+import { useTranslation } from 'react-i18next';
 import {
   FlatList,
   StyleSheet,
@@ -10,9 +10,10 @@ import {
   TouchableOpacity,
   View,
 } from 'react-native';
-import { useTranslation } from 'react-i18next';
 
 import { InlineTip, ITEM_HEIGHT, Legend, MonthBlock } from '@/components/menstrual-cycle';
+import { HeaderBar } from '@/components/ui/HeaderBar';
+import { useSafeAreaTop } from '@/hooks/useSafeAreaWithPadding';
 import {
   deleteMenstrualFlow,
   fetchMenstrualFlowSamples,
@@ -29,14 +30,22 @@ type TabKey = 'cycle' | 'analysis';
 
 export default function MenstrualCycleScreen() {
   const router = useRouter();
-  const { t } = useTranslation();
+  const { t, i18n } = useTranslation();
+  const safeAreaTop = useSafeAreaTop();
   const [records, setRecords] = useState<CycleRecord[]>([]);
   const [windowConfig, setWindowConfig] = useState({ before: 2, after: 3 });
+  const locale = i18n.language.startsWith('en') ? 'en' : 'zh';
+  const monthTitleFormat = t('menstrual.dateFormats.monthTitle', { defaultValue: 'M月' });
+  const monthSubtitleFormat = t('menstrual.dateFormats.monthSubtitle', { defaultValue: 'YYYY年' });
+  const weekLabels = useMemo(() => {
+    const labels = t('menstrual.weekdays', { returnObjects: true }) as string[];
+    return Array.isArray(labels) && labels.length === 7 ? labels : undefined;
+  }, [t]);
 
-  // Load data from HealthKit
+  // 从 HealthKit 拉取当前窗口范围内的经期数据
   useEffect(() => {
     const loadData = async () => {
-      // Calculate date range based on windowConfig
+      // 根据 windowConfig 计算需要拉取的月份区间
       const today = dayjs();
       const startDate = today.subtract(windowConfig.before, 'month').startOf('month').toDate();
       const endDate = today.add(windowConfig.after, 'month').endOf('month').toDate();
@@ -49,6 +58,7 @@ export default function MenstrualCycleScreen() {
     loadData();
   }, [windowConfig]);
 
+  // 根据记录生成时间轴（包含预测周期、易孕期等）
   const timeline = useMemo(
     () =>
       buildMenstrualTimeline({
@@ -56,8 +66,11 @@ export default function MenstrualCycleScreen() {
         monthsAfter: windowConfig.after,
         records,
         defaultPeriodLength: DEFAULT_PERIOD_LENGTH,
+        locale,
+        monthTitleFormat,
+        monthSubtitleFormat,
       }),
-    [records, windowConfig]
+    [records, windowConfig, locale, monthSubtitleFormat, monthTitleFormat]
   );
   const [activeTab, setActiveTab] = useState<TabKey>('cycle');
   const [selectedDateKey, setSelectedDateKey] = useState(
@@ -67,11 +80,28 @@ export default function MenstrualCycleScreen() {
   const offsetRef = useRef(0);
   const prependDeltaRef = useRef(0);
   const loadingPrevRef = useRef(false);
+  const hasAutoScrolledRef = useRef(false);
+  const todayMonthId = useMemo(() => dayjs().format('YYYY-MM'), []);
 
   const selectedInfo = timeline.dayMap[selectedDateKey];
   const selectedDate = dayjs(selectedDateKey);
+  const initialMonthIndex = useMemo(
+    () => timeline.months.findIndex((month) => month.id === todayMonthId),
+    [timeline.months, todayMonthId]
+  );
+
+  useEffect(() => {
+    if (hasAutoScrolledRef.current) return;
+    if (initialMonthIndex < 0 || !listRef.current) return;
+    hasAutoScrolledRef.current = true;
+    offsetRef.current = initialMonthIndex * ITEM_HEIGHT;
+    requestAnimationFrame(() => {
+      listRef.current?.scrollToIndex({ index: initialMonthIndex, animated: false });
+    });
+  }, [initialMonthIndex]);
 
  
+  // 标记当天为经期开始（包含乐观更新与 HealthKit 同步）
   const handleMarkStart = async () => {
     if (selectedDate.isAfter(dayjs(), 'day')) return;
 
@@ -176,6 +206,7 @@ export default function MenstrualCycleScreen() {
     }
   };
 
+  // 取消选中日期的经期标记（与 HealthKit 同步）
   const handleCancelMark = async () => {
     if (!selectedInfo || !selectedInfo.confirmed) return;
     if (selectedDate.isAfter(dayjs(), 'day')) return;
@@ -237,6 +268,7 @@ export default function MenstrualCycleScreen() {
     }
   };
 
+  // 下拉到顶部时加载更早的月份
   const handleLoadPrevious = () => {
     if (loadingPrevRef.current) return;
     loadingPrevRef.current = true;
@@ -245,6 +277,7 @@ export default function MenstrualCycleScreen() {
     setWindowConfig((prev) => ({ ...prev, before: prev.before + delta }));
   };
 
+  // 向前追加月份时，保持当前视口位置不跳动
   useEffect(() => {
     if (prependDeltaRef.current > 0 && listRef.current) {
       const offset = offsetRef.current + prependDeltaRef.current * ITEM_HEIGHT;
@@ -260,6 +293,7 @@ export default function MenstrualCycleScreen() {
     viewAreaCoveragePercentThreshold: 10,
   }).current;
 
+  // 监测可视区域，接近顶部时触发加载更早月份
   const onViewableItemsChanged = useRef(({ viewableItems }: any) => {
     const minIndex = viewableItems.reduce(
       (acc: number, cur: any) => Math.min(acc, cur.index ?? acc),
@@ -272,6 +306,7 @@ export default function MenstrualCycleScreen() {
 
 
 
+  // FlatList 数据源：按月份拆分
   const listData = useMemo(() => {
     return timeline.months.map((m) => ({
       type: 'month' as const,
@@ -305,6 +340,7 @@ export default function MenstrualCycleScreen() {
             selectedDateKey={selectedDateKey}
             onSelect={(key) => setSelectedDateKey(key)}
             renderTip={renderInlineTip}
+            weekLabels={weekLabels}
           />
         )}
         showsVerticalScrollIndicator={false}
@@ -313,6 +349,19 @@ export default function MenstrualCycleScreen() {
         maxToRenderPerBatch={4}
         removeClippedSubviews
         contentContainerStyle={styles.listContent}
+        // 使用固定高度优化初始滚动定位
+        getItemLayout={(_, index) => ({
+          length: ITEM_HEIGHT,
+          offset: ITEM_HEIGHT * index,
+          index,
+        })}
+        initialScrollIndex={initialMonthIndex >= 0 ? initialMonthIndex : undefined}
+        onScrollToIndexFailed={({ index }) => {
+          listRef.current?.scrollToOffset({
+            offset: ITEM_HEIGHT * index,
+            animated: false,
+          });
+        }}
         viewabilityConfig={viewabilityConfig}
         onViewableItemsChanged={onViewableItemsChanged}
         onScroll={(e) => {
@@ -344,15 +393,30 @@ export default function MenstrualCycleScreen() {
         end={{ x: 0, y: 1 }}
       />
 
-      <View style={styles.header}>
-        <TouchableOpacity onPress={() => router.back()} style={styles.headerIcon}>
-          <Ionicons name="chevron-back" size={22} color="#0f172a" />
-        </TouchableOpacity>
-        <Text style={styles.headerTitle}>{t('menstrual.screen.header')}</Text>
-        <TouchableOpacity style={styles.headerIcon}>
-          <Ionicons name="settings-outline" size={20} color="#0f172a" />
-        </TouchableOpacity>
-      </View>
+      <HeaderBar
+        title={t('menstrual.screen.header')}
+        onBack={() => router.back()}
+        // right={
+        //   isLiquidGlassAvailable() ? (
+        //     <TouchableOpacity style={styles.headerIconButton} activeOpacity={0.7}>
+        //       <GlassView
+        //         style={styles.headerIconGlass}
+        //         glassEffectStyle="clear"
+        //         tintColor="rgba(255, 255, 255, 0.35)"
+        //         isInteractive={true}
+        //       >
+        //         <Ionicons name="settings-outline" size={20} color="#0f172a" />
+        //       </GlassView>
+        //     </TouchableOpacity>
+        //   ) : (
+        //     <TouchableOpacity style={styles.headerIcon} activeOpacity={0.7}>
+        //       <Ionicons name="settings-outline" size={20} color="#0f172a" />
+        //     </TouchableOpacity>
+        //   )
+        // }
+      />
+
+      <View style={{ height: safeAreaTop }} />
 
       <View style={styles.tabSwitcher}>
         {([
@@ -383,29 +447,29 @@ export default function MenstrualCycleScreen() {
 const styles = StyleSheet.create({
   container: {
     flex: 1,
-    paddingTop: 52,
     paddingHorizontal: 16,
     backgroundColor: 'transparent',
   },
-  header: {
-    flexDirection: 'row',
-    alignItems: 'center',
-    justifyContent: 'space-between',
-    marginBottom: 12,
-  },
   headerIcon: {
     width: 36,
     height: 36,
     borderRadius: 18,
     alignItems: 'center',
     justifyContent: 'center',
-    backgroundColor: 'rgba(255,255,255,0.9)',
+    backgroundColor: 'rgba(255, 255, 255, 0.5)',
   },
-  headerTitle: {
-    fontSize: 18,
-    fontWeight: '800',
-    color: '#0f172a',
-    fontFamily: 'AliBold',
+  headerIconButton: {
+    width: 36,
+    height: 36,
+    borderRadius: 18,
+    overflow: 'hidden',
+  },
+  headerIconGlass: {
+    width: 36,
+    height: 36,
+    borderRadius: 18,
+    alignItems: 'center',
+    justifyContent: 'center',
   },
   tabSwitcher: {
     flexDirection: 'row',
diff --git a/components/MenstrualCycleCard.tsx b/components/MenstrualCycleCard.tsx
index 82ba0b2..3f3870b 100644
--- a/components/MenstrualCycleCard.tsx
+++ b/components/MenstrualCycleCard.tsx
@@ -1,11 +1,11 @@
-import { LinearGradient } from 'expo-linear-gradient';
 import dayjs, { Dayjs } from 'dayjs';
+import { LinearGradient } from 'expo-linear-gradient';
 import React, { useEffect, useMemo, useState } from 'react';
-import { StyleSheet, Text, TouchableOpacity, View } from 'react-native';
 import { useTranslation } from 'react-i18next';
+import { StyleSheet, Text, TouchableOpacity, View } from 'react-native';
 
 import { Colors } from '@/constants/Colors';
-import { fetchMenstrualFlowSamples } from '@/utils/health';
+import { fetchMenstrualFlowSamples, healthDataEvents } from '@/utils/health';
 import {
   buildMenstrualTimeline,
   convertHealthKitSamplesToCycleRecords,
@@ -49,7 +49,10 @@ export const MenstrualCycleCard: React.FC<Props> = ({ onPress }) => {
   useEffect(() => {
     let mounted = true;
     const loadMenstrualData = async () => {
-      setLoading(true);
+      // Avoid setting loading to true for background updates to prevent UI flicker
+      if (records.length === 0) {
+        setLoading(true);
+      }
       try {
         const today = dayjs();
         const startDate = today.subtract(3, 'month').startOf('month').toDate();
@@ -72,8 +75,16 @@ export const MenstrualCycleCard: React.FC<Props> = ({ onPress }) => {
     };
 
     loadMenstrualData();
+
+    // Listen for data changes
+    const handleDataChange = () => {
+      loadMenstrualData();
+    };
+    healthDataEvents.on('menstrualDataChanged', handleDataChange);
+
     return () => {
       mounted = false;
+      healthDataEvents.off('menstrualDataChanged', handleDataChange);
     };
   }, []);
 
diff --git a/components/menstrual-cycle/DayCell.tsx b/components/menstrual-cycle/DayCell.tsx
index 48fb0da..a040105 100644
--- a/components/menstrual-cycle/DayCell.tsx
+++ b/components/menstrual-cycle/DayCell.tsx
@@ -1,10 +1,12 @@
 import { Colors } from '@/constants/Colors';
 import React from 'react';
+import { useTranslation } from 'react-i18next';
 import { StyleSheet, Text, TouchableOpacity, View } from 'react-native';
 import { STATUS_COLORS } from './constants';
 import { DayCellProps } from './types';
 
 export const DayCell: React.FC<DayCellProps> = ({ cell, isSelected, onPress }) => {
+  const { t } = useTranslation();
   const status = cell.info?.status;
   const colors = status ? STATUS_COLORS[status] : undefined;
 
@@ -32,7 +34,7 @@ export const DayCell: React.FC<DayCellProps> = ({ cell, isSelected, onPress }) =
           {cell.label}
         </Text>
       </View>
-      {cell.isToday && <Text style={styles.todayText}>今天</Text>}
+      {cell.isToday && <Text style={styles.todayText}>{t('menstrual.today')}</Text>}
     </TouchableOpacity>
   );
 };
diff --git a/components/menstrual-cycle/InlineTip.tsx b/components/menstrual-cycle/InlineTip.tsx
index c7340e0..b1082f6 100644
--- a/components/menstrual-cycle/InlineTip.tsx
+++ b/components/menstrual-cycle/InlineTip.tsx
@@ -1,7 +1,10 @@
 import { Colors } from '@/constants/Colors';
 import { Ionicons } from '@expo/vector-icons';
 import dayjs from 'dayjs';
+import 'dayjs/locale/en';
+import 'dayjs/locale/zh-cn';
 import React from 'react';
+import { useTranslation } from 'react-i18next';
 import { DimensionValue, StyleSheet, Text, TouchableOpacity, View } from 'react-native';
 import { InlineTipProps } from './types';
 
@@ -12,9 +15,12 @@ export const InlineTip: React.FC<InlineTipProps> = ({
   onMarkStart,
   onCancelMark,
 }) => {
+  const { t, i18n } = useTranslation();
   // 14.28% per cell. Center is 7.14%.
   const pointerLeft = `${columnIndex * 14.2857 + 7.1428}%` as DimensionValue;
   const isFuture = selectedDate.isAfter(dayjs(), 'day');
+  const localeKey = i18n.language.startsWith('en') ? 'en' : 'zh-cn';
+  const dateFormat = t('menstrual.dateFormatShort', { defaultValue: 'M月D日' });
 
   return (
     <View style={styles.inlineTipCard}>
@@ -22,17 +28,19 @@ export const InlineTip: React.FC<InlineTipProps> = ({
       <View style={styles.inlineTipRow}>
         <View style={styles.inlineTipDate}>
           <Ionicons name="calendar-outline" size={16} color="#111827" />
-          <Text style={styles.inlineTipDateText}>{selectedDate.format('M月D日')}</Text>
+          <Text style={styles.inlineTipDateText}>
+            {selectedDate.locale(localeKey).format(dateFormat)}
+          </Text>
         </View>
         {!isFuture && (!selectedInfo || !selectedInfo.confirmed) && (
           <TouchableOpacity style={styles.inlinePrimaryBtn} onPress={onMarkStart}>
             <Ionicons name="add" size={14} color="#fff" />
-            <Text style={styles.inlinePrimaryText}>标记经期</Text>
+            <Text style={styles.inlinePrimaryText}>{t('menstrual.actions.markPeriod')}</Text>
           </TouchableOpacity>
         )}
         {!isFuture && selectedInfo?.confirmed && selectedInfo.status === 'period' && (
           <TouchableOpacity style={styles.inlineSecondaryBtn} onPress={onCancelMark}>
-            <Text style={styles.inlineSecondaryText}>取消标记</Text>
+            <Text style={styles.inlineSecondaryText}>{t('menstrual.actions.cancelMark')}</Text>
           </TouchableOpacity>
         )}
       </View>
diff --git a/components/menstrual-cycle/Legend.tsx b/components/menstrual-cycle/Legend.tsx
index 05aabce..24b3950 100644
--- a/components/menstrual-cycle/Legend.tsx
+++ b/components/menstrual-cycle/Legend.tsx
@@ -1,19 +1,21 @@
 import React from 'react';
+import { useTranslation } from 'react-i18next';
 import { StyleSheet, Text, View } from 'react-native';
 import { STATUS_COLORS } from './constants';
 import { LegendItem } from './types';
 
-const LEGEND_ITEMS: LegendItem[] = [
-  { label: '经期', key: 'period' },
-  { label: '预测经期', key: 'predicted-period' },
-  { label: '排卵期', key: 'fertile' },
-  { label: '排卵日', key: 'ovulation-day' },
-];
-
 export const Legend: React.FC = () => {
+  const { t } = useTranslation();
+  const legendItems: LegendItem[] = [
+    { label: t('menstrual.legend.period'), key: 'period' },
+    { label: t('menstrual.legend.predictedPeriod'), key: 'predicted-period' },
+    { label: t('menstrual.legend.fertile'), key: 'fertile' },
+    { label: t('menstrual.legend.ovulation'), key: 'ovulation-day' },
+  ];
+
   return (
     <View style={styles.legendRow}>
-      {LEGEND_ITEMS.map((item) => (
+      {legendItems.map((item) => (
         <View key={item.key} style={styles.legendItem}>
           <View
             style={[
diff --git a/components/menstrual-cycle/MonthBlock.tsx b/components/menstrual-cycle/MonthBlock.tsx
index b776439..2f1ef7d 100644
--- a/components/menstrual-cycle/MonthBlock.tsx
+++ b/components/menstrual-cycle/MonthBlock.tsx
@@ -17,6 +17,7 @@ interface MonthBlockProps {
   selectedDateKey: string;
   onSelect: (dateKey: string) => void;
   renderTip: (colIndex: number) => React.ReactNode;
+  weekLabels?: string[];
 }
 
 export const MonthBlock: React.FC<MonthBlockProps> = ({
@@ -24,8 +25,10 @@ export const MonthBlock: React.FC<MonthBlockProps> = ({
   selectedDateKey,
   onSelect,
   renderTip,
+  weekLabels,
 }) => {
   const weeks = useMemo(() => chunkArray(month.cells, 7), [month.cells]);
+  const labels = weekLabels?.length === 7 ? weekLabels : WEEK_LABELS;
 
   return (
     <View style={styles.monthCard}>
@@ -34,7 +37,7 @@ export const MonthBlock: React.FC<MonthBlockProps> = ({
         <Text style={styles.monthSubtitle}>{month.subtitle}</Text>
       </View>
       <View style={styles.weekRow}>
-        {WEEK_LABELS.map((label) => (
+        {labels.map((label) => (
           <Text key={label} style={styles.weekLabel}>
             {label}
           </Text>
diff --git a/components/workout/WorkoutDetailModal.tsx b/components/workout/WorkoutDetailModal.tsx
index 3fb1c76..901f0fa 100644
--- a/components/workout/WorkoutDetailModal.tsx
+++ b/components/workout/WorkoutDetailModal.tsx
@@ -9,7 +9,6 @@ import {
   ActivityIndicator,
   Dimensions,
   Modal,
-  Platform,
   Pressable,
   ScrollView,
   Share,
@@ -19,7 +18,7 @@ import {
   TouchableWithoutFeedback,
   View,
 } from 'react-native';
-import ViewShot from 'react-native-view-shot';
+import ViewShot, { captureRef } from 'react-native-view-shot';
 
 import { useI18n } from '@/hooks/useI18n';
 import {
@@ -156,7 +155,7 @@ export function WorkoutDetailModal({
         type: 'info',
         text1: t('workoutDetail.share.generating', '正在生成分享卡片…'),
       });
-      const uri = await shareContentRef.current.capture?.({
+      const uri = await captureRef(shareContentRef, {
         format: 'png',
         quality: 0.95,
         snapshotContentContainer: true,
@@ -164,6 +163,7 @@ export function WorkoutDetailModal({
       if (!uri) {
         throw new Error('share-capture-failed');
       }
+      const shareUri = uri.startsWith('file://') ? uri : `file://${uri}`;
       const shareTitle = t('workoutDetail.share.title', { defaultValue: activityName || t('workoutDetail.title', '锻炼详情') });
       const caloriesLabel = metrics?.calories != null
         ? `${metrics.calories} ${t('workoutDetail.metrics.caloriesUnit')}`
@@ -179,7 +179,7 @@ export function WorkoutDetailModal({
       await Share.share({
         title: shareTitle,
         message: shareMessage,
-        url: Platform.OS === 'ios' ? uri : `file://${uri}`,
+        url: shareUri,
       });
     } catch (error) {
       console.warn('workout-detail-share-failed', error);
@@ -487,7 +487,6 @@ export function WorkoutDetailModal({
         <ViewShot
           ref={shareContentRef}
           style={[styles.sheetContainer, styles.shareCaptureContainer]}
-          collapsable={false}
           options={{ format: 'png', quality: 0.95, snapshotContentContainer: true }}
         >
           <LinearGradient
diff --git a/i18n/en/menstrual.ts b/i18n/en/menstrual.ts
index 157cf19..ec48f73 100644
--- a/i18n/en/menstrual.ts
+++ b/i18n/en/menstrual.ts
@@ -1,5 +1,21 @@
 export const menstrual = {
   dateFormatShort: 'MMM D',
+  dateFormats: {
+    monthTitle: 'MMM',
+    monthSubtitle: 'YYYY',
+  },
+  weekdays: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'],
+  today: 'Today',
+  legend: {
+    period: 'Period',
+    predictedPeriod: 'Predicted period',
+    fertile: 'Fertile window',
+    ovulation: 'Ovulation',
+  },
+  actions: {
+    markPeriod: 'Mark period',
+    cancelMark: 'Cancel',
+  },
   card: {
     title: 'Menstrual cycle',
     syncingState: 'Syncing',
diff --git a/i18n/zh/menstrual.ts b/i18n/zh/menstrual.ts
index 1e1cc13..83ded60 100644
--- a/i18n/zh/menstrual.ts
+++ b/i18n/zh/menstrual.ts
@@ -1,5 +1,21 @@
 export const menstrual = {
   dateFormatShort: 'M月D日',
+  dateFormats: {
+    monthTitle: 'M月',
+    monthSubtitle: 'YYYY年',
+  },
+  weekdays: ['一', '二', '三', '四', '五', '六', '日'],
+  today: '今天',
+  legend: {
+    period: '经期',
+    predictedPeriod: '预测经期',
+    fertile: '排卵期',
+    ovulation: '排卵日',
+  },
+  actions: {
+    markPeriod: '标记经期',
+    cancelMark: '取消标记',
+  },
   card: {
     title: '生理周期',
     syncingState: '同步中',
diff --git a/utils/health.ts b/utils/health.ts
index c3d2897..e689789 100644
--- a/utils/health.ts
+++ b/utils/health.ts
@@ -271,6 +271,9 @@ class HealthPermissionManager extends SimpleEventEmitter {
 // 全局权限管理实例
 export const healthPermissionManager = new HealthPermissionManager();
 
+// 全局健康数据事件发射器
+export const healthDataEvents = new SimpleEventEmitter();
+
 // Interface for activity summary data from HealthKit
 export interface HealthActivitySummary {
   activeEnergyBurned: number;
@@ -1632,6 +1635,8 @@ export async function saveMenstrualFlow(
     const result = await HealthKitManager.saveMenstrualFlow(options);
     if (result && result.success) {
       console.log('经期数据保存成功');
+      // 触发数据变更事件
+      healthDataEvents.emit('menstrualDataChanged');
       return true;
     }
     console.error('经期数据保存失败');
@@ -1655,6 +1660,8 @@ export async function deleteMenstrualFlow(
     const result = await HealthKitManager.deleteMenstrualFlow(options);
     if (result && result.success) {
       console.log(`经期数据删除成功，数量: ${result.count}`);
+      // 触发数据变更事件
+      healthDataEvents.emit('menstrualDataChanged');
       return true;
     }
     console.error('经期数据删除失败');
diff --git a/utils/menstrualCycle.ts b/utils/menstrualCycle.ts
index 9ce8b04..bea5400 100644
--- a/utils/menstrualCycle.ts
+++ b/utils/menstrualCycle.ts
@@ -1,4 +1,6 @@
 import dayjs, { Dayjs } from 'dayjs';
+import 'dayjs/locale/en';
+import 'dayjs/locale/zh-cn';
 import { MenstrualFlowSample } from './health';
 
 export type MenstrualDayStatus = 'period' | 'predicted-period' | 'fertile' | 'ovulation-day';
@@ -153,6 +155,9 @@ export const buildMenstrualTimeline = (options?: {
   monthsAfter?: number;
   defaultCycleLength?: number;
   defaultPeriodLength?: number;
+  locale?: 'zh' | 'en';
+  monthTitleFormat?: string;
+  monthSubtitleFormat?: string;
 }): MenstrualTimeline => {
   const today = dayjs();
   const monthsBefore = options?.monthsBefore ?? 2;
@@ -267,6 +272,11 @@ export const buildMenstrualTimeline = (options?: {
   const months: MenstrualMonth[] = [];
   let monthCursor = startMonth.startOf('month');
 
+  const locale = options?.locale ?? 'zh';
+  const localeKey = locale === 'en' ? 'en' : 'zh-cn';
+  const monthTitleFormat = options?.monthTitleFormat ?? (locale === 'en' ? 'MMM' : 'M月');
+  const monthSubtitleFormat = options?.monthSubtitleFormat ?? (locale === 'en' ? 'YYYY' : 'YYYY年');
+
   while (monthCursor.isBefore(endMonth) || monthCursor.isSame(endMonth, 'month')) {
     const firstDay = monthCursor.startOf('month');
     const daysInMonth = firstDay.daysInMonth();
@@ -298,10 +308,12 @@ export const buildMenstrualTimeline = (options?: {
       });
     }
 
+    const formattedMonth = firstDay.locale(localeKey);
+
     months.push({
       id: firstDay.format('YYYY-MM'),
-      title: firstDay.format('M月'),
-      subtitle: firstDay.format('YYYY年'),
+      title: formattedMonth.format(monthTitleFormat),
+      subtitle: formattedMonth.format(monthSubtitleFormat),
       cells,
     });