diff --git a/src/components/BirthdatePicker.vue b/src/components/BirthdatePicker.vue
new file mode 100644
index 0000000..fb96332
--- /dev/null
+++ b/src/components/BirthdatePicker.vue
@@ -0,0 +1,262 @@
+<template>
+	<div class="birthdate-picker">
+		<t-radio-group class="mode" v-model="calendarProxy" variant="default-filled">
+			<t-radio :block="false" borderless value="SOLAR">公历</t-radio>
+			<t-radio :block="false" borderless value="LUNAR">农历</t-radio>
+			<t-button
+				v-if="modelValue"
+				class="clear"
+				size="extra-small"
+				@click="clearValue"
+			>
+				清除
+			</t-button>
+		</t-radio-group>
+		<div class="value" @click="openPicker">
+			<span :class="{ placeholder: !displayValue }" v-text="displayValue || placeholder" />
+			<t-icon name="chevron-right" size="1.25rem" />
+		</div>
+		<t-popup v-model="visible" placement="bottom">
+			<t-date-time-picker
+				v-if="calendarProxy === 'SOLAR'"
+				:title="'选择公历出生日期'"
+				mode="date"
+				:value="solarDraft"
+				:start="startDate"
+				:end="today"
+				format="YYYY-MM-DD"
+				cancel-btn="取消"
+				confirm-btn="确定"
+				@cancel="visible = false"
+				@confirm="handleSolarConfirm"
+			/>
+			<t-picker
+				v-else
+				title="选择农历出生日期"
+				:columns="lunarColumns"
+				:value="lunarPickerValue"
+				cancel-btn="取消"
+				confirm-btn="确定"
+				@pick="handleLunarPick"
+				@cancel="visible = false"
+				@confirm="handleLunarConfirm"
+			/>
+		</t-popup>
+	</div>
+</template>
+
+<script setup lang="ts">
+import { LunarCalendar, type LunarDate } from "@/utils/LunarCalendar";
+
+defineOptions({
+	name: "BirthdatePicker"
+});
+
+type BirthdateCalendar = "SOLAR" | "LUNAR";
+type PickerValue = string | number;
+
+const props = withDefaults(defineProps<{
+	modelValue?: string;
+	calendar?: BirthdateCalendar;
+	placeholder?: string;
+}>(), {
+	modelValue: "",
+	calendar: "SOLAR",
+	placeholder: "请选择出生日期"
+});
+
+const emit = defineEmits<{
+	(e: "update:modelValue", value: string): void;
+	(e: "update:calendar", value: BirthdateCalendar): void;
+}>();
+
+const startDate = `${LunarCalendar.startYear}-01-31`;
+const today = LunarCalendar.today();
+const visible = ref(false);
+const solarDraft = ref(today);
+const lunarDraft = ref<LunarDate>(LunarCalendar.solarToLunar(today) || {
+	year: LunarCalendar.startYear,
+	month: 1,
+	day: 1,
+	isLeap: false
+});
+
+const calendarProxy = computed<BirthdateCalendar>({
+	get: () => props.calendar,
+	set: value => emit("update:calendar", value)
+});
+const displayValue = computed(() => {
+	if (!props.modelValue) {
+		return "";
+	}
+	if (calendarProxy.value === "SOLAR") {
+		return props.modelValue;
+	}
+	const lunarDate = LunarCalendar.solarToLunar(props.modelValue);
+	return lunarDate ? LunarCalendar.formatLunarDate(lunarDate) : props.modelValue;
+});
+const lunarPickerValue = computed(() => [
+	`${lunarDraft.value.year}`,
+	`${lunarDraft.value.month}${lunarDraft.value.isLeap ? "-leap" : ""}`,
+	`${lunarDraft.value.day}`
+]);
+const lunarColumns = computed(() => {
+	const yearOptions = LunarCalendar.getYearOptions(today);
+	const monthOptions = LunarCalendar.getMonthOptions(lunarDraft.value.year)
+		.filter(option => isLunarDateSelectable({
+			year: lunarDraft.value.year,
+			month: option.month,
+			day: 1,
+			isLeap: option.isLeap
+		}));
+	const selectedMonth = monthOptions.some(option => option.value === lunarPickerValue.value[1])
+		? lunarPickerValue.value[1]
+		: monthOptions[0]?.value;
+	const selectedOption = monthOptions.find(option => option.value === selectedMonth) || monthOptions[0];
+	const dayCount = selectedOption ? LunarCalendar.getMonthDays({
+		year: lunarDraft.value.year,
+		month: selectedOption.month,
+		isLeap: selectedOption.isLeap
+	}) : 29;
+	const dayOptions = Array.from({ length: dayCount }, (_, index) => {
+		const day = index + 1;
+		return {
+			value: `${day}`,
+			label: LunarCalendar.formatLunarDate({
+				year: lunarDraft.value.year,
+				month: selectedOption?.month || 1,
+				day,
+				isLeap: selectedOption?.isLeap || false
+			})
+				.split(" ")
+				.slice(-1)[0] || `${day}`
+		};
+	}).filter(option => isLunarDateSelectable({
+		year: lunarDraft.value.year,
+		month: selectedOption?.month || 1,
+		day: Number(option.value),
+		isLeap: selectedOption?.isLeap || false
+	}));
+	return [
+		yearOptions,
+		monthOptions,
+		dayOptions
+	];
+});
+
+function openPicker(): void {
+	if (calendarProxy.value === "SOLAR") {
+		solarDraft.value = props.modelValue || today;
+	} else {
+		const lunarDate = props.modelValue ? LunarCalendar.solarToLunar(props.modelValue) : LunarCalendar.solarToLunar(today);
+		if (lunarDate) {
+			lunarDraft.value = lunarDate;
+		}
+	}
+	visible.value = true;
+}
+
+function handleSolarConfirm(value: PickerValue): void {
+	const date = String(value);
+	if (!date) {
+		return;
+	}
+	emit("update:modelValue", date);
+	visible.value = false;
+}
+
+function handleLunarPick(value: PickerValue[]): void {
+	applyLunarPickerValue(value);
+}
+
+function handleLunarConfirm(value: PickerValue[]): void {
+	applyLunarPickerValue(value);
+	const solarDate = LunarCalendar.lunarToSolar(lunarDraft.value);
+	if (!solarDate || solarDate > today) {
+		return;
+	}
+	emit("update:modelValue", solarDate);
+	visible.value = false;
+}
+
+function applyLunarPickerValue(value: PickerValue[]): void {
+	const year = Number(value[0]);
+	const monthValue = String(value[1] || "1");
+	const monthOptions = LunarCalendar.getMonthOptions(year)
+		.filter(option => isLunarDateSelectable({
+			year,
+			month: option.month,
+			day: 1,
+			isLeap: option.isLeap
+		}));
+	const selectedMonth = monthOptions.find(option => option.value === monthValue) || monthOptions[0];
+	const day = Number(value[2]);
+	if (!year || !selectedMonth || !day) {
+		return;
+	}
+	const monthDays = LunarCalendar.getMonthDays({
+		year,
+		month: selectedMonth.month,
+		isLeap: selectedMonth.isLeap
+	});
+	lunarDraft.value = {
+		year,
+		month: selectedMonth.month,
+		day: Math.max(1, Math.min(day, monthDays)),
+		isLeap: selectedMonth.isLeap
+	};
+}
+
+function isLunarDateSelectable(lunarDate: LunarDate): boolean {
+	const solarDate = LunarCalendar.lunarToSolar(lunarDate);
+	return !!solarDate && solarDate <= today;
+}
+
+function clearValue(): void {
+	emit("update:modelValue", "");
+	visible.value = false;
+}
+</script>
+
+<style scoped lang="less">
+.birthdate-picker {
+	gap: .5rem;
+	display: flex;
+	flex-direction: column;
+
+	.mode {
+		gap: .5rem;
+		display: flex;
+	}
+
+	.value {
+		gap: .25rem;
+		flex: 1;
+		display: flex;
+		min-width: 0;
+		align-items: center;
+		justify-content: space-between;
+
+		span {
+			line-height: 1.5;
+		}
+
+		.placeholder {
+			color: var(--td-text-color-placeholder);
+		}
+	}
+
+	.clear {
+		flex: none;
+	}
+}
+
+:global(html.theme-dark) {
+	.birthdate-picker {
+
+		.placeholder {
+			color: #94a3b8;
+		}
+	}
+}
+</style>
diff --git a/src/pages/management/CustomerDetail.vue b/src/pages/management/CustomerDetail.vue
index 80e27f0..49b965f 100644
--- a/src/pages/management/CustomerDetail.vue
+++ b/src/pages/management/CustomerDetail.vue
@@ -5,6 +5,18 @@
 			:customer="customer"
 		/>
 		<t-cell-group v-if="customer" theme="card">
+			<t-cell title="出生日期">
+				<button
+					v-if="isLunarBirthdate"
+					class="birthdate-trigger"
+					type="button"
+					@click.stop="toggleBirthdateText"
+				>
+					<span v-text="birthdateText" />
+				</button>
+				<span v-else v-text="birthdateText" />
+			</t-cell>
+			<t-cell title="年龄" :note="ageText" />
 			<t-cell title="住址" :note="customer.address || '无'" />
 			<t-cell title="病症" :note="customer.disease || '无'" />
 			<t-cell title="备注" :note="customer.remark || '无'" />
@@ -162,6 +174,7 @@ import { useSettingStore } from "@/store/settingStore";
 import type { BodyAreaValue, Customer } from "@/types/Customer";
 import { getCustomerPhotoURL, normalizeBodyAreaValue } from "@/utils/customer";
 import { gaoPermissionCodes } from "@/utils/gaoPermission";
+import { LunarCalendar } from "@/utils/LunarCalendar";
 
 defineOptions({
 	name: "CustomerDetail"
@@ -180,6 +193,7 @@ const scanPopupVisible = ref(false);
 const pendingInvitee = ref<Customer>();
 const scanStatus = ref("点击扫码开始识别。");
 const removing = ref(false);
+const showSolarBirthdate = ref(false);
 let latestDecodedText = "";
 
 const inviter = computed(() => customer.value?.introducerCustomer);
@@ -189,6 +203,10 @@ const creatorName = computed(() => {
 	return creatorUser?.nick || creatorUser?.name || customer.value?.creatorUserId || "无";
 });
 const createdAtText = computed(() => formatTime(customer.value?.createdAt));
+const isLunarBirthdate = computed(() => customer.value?.birthdateCalendar === "LUNAR" && !!customer.value?.birthdate);
+const solarBirthdateText = computed(() => formatSolarBirthdate(customer.value));
+const birthdateText = computed(() => showSolarBirthdate.value && isLunarBirthdate.value ? solarBirthdateText.value : formatBirthdate(customer.value));
+const ageText = computed(() => customer.value?.age === undefined || customer.value?.age === null ? "无" : `${customer.value.age} 岁`);
 const selectedAreas = computed<BodyAreaValue>({
 	get() {
 		return normalizeBodyAreaValue(customer.value?.conditioningPart);
@@ -203,10 +221,12 @@ async function loadCustomer(): Promise<void> {
 	if (!id) {
 		customer.value = undefined;
 		invitees.value = [];
+		showSolarBirthdate.value = false;
 		return;
 	}
 
 	try {
+		showSolarBirthdate.value = false;
 		customer.value = await CustomerAPI.detail(id);
 		await loadInvitees();
 	} catch (err) {
@@ -297,6 +317,27 @@ function formatTime(value?: number): string {
 	return Time.formatDateTime(date);
 }
 
+function formatBirthdate(value?: Customer): string {
+	if (!value?.birthdate) {
+		return "无";
+	}
+	if (value.birthdateCalendar !== "LUNAR") {
+		return `公历 ${value.birthdate}`;
+	}
+	const lunarDate = LunarCalendar.solarToLunar(value.birthdate);
+	return lunarDate ? LunarCalendar.formatLunarDate(lunarDate) : "农历日期";
+}
+
+function formatSolarBirthdate(value?: Customer): string {
+	return value?.birthdate ? `公历 ${value.birthdate}` : "无";
+}
+
+function toggleBirthdateText(): void {
+	if (isLunarBirthdate.value) {
+		showSolarBirthdate.value = !showSolarBirthdate.value;
+	}
+}
+
 function isCustomerAncestor(invitee: Customer): boolean {
 	if (!customer.value?.id) {
 		return false;
@@ -519,6 +560,17 @@ watch(() => route.params.id, async () => {
 	}
 }
 
+.birthdate-trigger {
+	padding: 0;
+	border: 0;
+	color: var(--td-text-color-primary);
+	font: inherit;
+	background: transparent;
+	text-align: right;
+	text-decoration: underline dotted;
+	text-underline-offset: .2rem;
+}
+
 .scan-popup {
 	gap: 1rem;
 	padding: 1rem 1rem calc(1rem + env(safe-area-inset-bottom, 0)) 1rem;
diff --git a/src/pages/management/CustomerEdit.vue b/src/pages/management/CustomerEdit.vue
index 3344ab5..4b1772c 100644
--- a/src/pages/management/CustomerEdit.vue
+++ b/src/pages/management/CustomerEdit.vue
@@ -34,11 +34,18 @@
 					borderless
 				/>
 			</t-form-item>
+			<t-form-item label="出生日期">
+				<birthdate-picker
+					v-model="formModel.birthdate"
+					v-model:calendar="formModel.birthdateCalendar"
+				/>
+			</t-form-item>
 			<t-form-item label="年龄">
 				<t-input
 					v-model.trim="formModel.age"
 					type="number"
-					placeholder="年龄"
+					:readonly="!!formModel.birthdate"
+					:placeholder="formModel.birthdate ? '根据出生日期自动计算' : '年龄'"
 					borderless
 				/>
 			</t-form-item>
@@ -157,7 +164,7 @@ import CodeScanner from "@/components/CodeScanner.vue";
 import CustomerSelector from "@/components/CustomerSelector.vue";
 import PhotoField from "@/components/PhotoField.vue";
 import { useSettingStore } from "@/store/settingStore";
-import type { BodyAreaValue, Customer, CustomerGender } from "@/types/Customer";
+import type { BodyAreaValue, Customer, CustomerBirthdateCalendar, CustomerGender } from "@/types/Customer";
 import { createBodyAreaValue, getCustomerPhotoURL, normalizeBodyAreaValue } from "@/utils/customer";
 import { gaoPermissionCodes } from "@/utils/gaoPermission";
 import { compressUploadImage } from "@/utils/imageCompression";
@@ -194,6 +201,8 @@ const formModel = reactive({
 	photoURL: "",
 	telephone: "",
 	age: "",
+	birthdate: "",
+	birthdateCalendar: "SOLAR" as CustomerBirthdateCalendar,
 	address: "",
 	referrer: "",
 	disease: "",
@@ -209,6 +218,8 @@ function resetFormModel(): void {
 		photoURL: "",
 		telephone: "",
 		age: "",
+		birthdate: "",
+		birthdateCalendar: "SOLAR",
 		address: "",
 		referrer: "",
 		disease: "",
@@ -258,6 +269,8 @@ async function fillForm(): Promise<void> {
 			photoURL: getCustomerPhotoURL(customer),
 			telephone: customer.telephone || "",
 			age: customer.age === undefined || customer.age === null ? "" : String(customer.age),
+			birthdate: customer.birthdate || "",
+			birthdateCalendar: customer.birthdateCalendar || "SOLAR",
 			address: customer.address || "",
 			referrer: customer.introducerCustomer?.name || "",
 			disease: customer.disease || "",
@@ -406,6 +419,8 @@ async function saveCustomer(): Promise<void> {
 		name: formModel.name,
 		gender: formModel.gender || undefined,
 		age: Number(formModel.age) || undefined,
+		birthdate: formModel.birthdate || null,
+		birthdateCalendar: formModel.birthdate ? formModel.birthdateCalendar : undefined,
 		telephone: formModel.telephone,
 		address: formModel.address,
 		remark: formModel.note,
@@ -463,6 +478,28 @@ watch(() => formModel.referrer, (value) => {
 	}
 });
 
+watch(() => formModel.birthdate, (value) => {
+	if (value) {
+		formModel.age = String(calculateAge(value));
+	}
+});
+
+function calculateAge(value: string): number {
+	const match = /^(\d{4})-(\d{2})-(\d{2})$/.exec(value);
+	if (!match) {
+		return 0;
+	}
+	const birthYear = Number(match[1]);
+	const birthMonth = Number(match[2]);
+	const birthDay = Number(match[3]);
+	const today = new Date();
+	let age = today.getFullYear() - birthYear;
+	if (today.getMonth() + 1 < birthMonth || (today.getMonth() + 1 === birthMonth && today.getDate() < birthDay)) {
+		age--;
+	}
+	return Math.max(age, 0);
+}
+
 onMounted(async () => {
 	await fillForm();
 });
diff --git a/src/types/Customer.ts b/src/types/Customer.ts
index 73f0c97..5845188 100644
--- a/src/types/Customer.ts
+++ b/src/types/Customer.ts
@@ -1,6 +1,7 @@
 import type { Attachment, Model, User } from "timi-web";
 
 export type CustomerGender = "MALE" | "FEMALE";
+export type CustomerBirthdateCalendar = "SOLAR" | "LUNAR";
 
 export type BodyAreaValue = {
 	selectedCodeList: string[];
@@ -11,6 +12,8 @@ export type Customer = {
 	name?: string;
 	gender?: CustomerGender;
 	age?: number;
+	birthdate?: string | null;
+	birthdateCalendar?: CustomerBirthdateCalendar;
 	telephone?: string;
 	address?: string;
 	remark?: string;
diff --git a/src/utils/LunarCalendar.ts b/src/utils/LunarCalendar.ts
new file mode 100644
index 0000000..cbb9050
--- /dev/null
+++ b/src/utils/LunarCalendar.ts
@@ -0,0 +1,221 @@
+export type LunarDate = {
+	year: number;
+	month: number;
+	day: number;
+	isLeap: boolean;
+};
+
+const START_YEAR = 1900;
+const START_DATE = Date.UTC(1900, 0, 31);
+const DAY_MS = 24 * 60 * 60 * 1000;
+const STEMS = ["甲", "乙", "丙", "丁", "戊", "己", "庚", "辛", "壬", "癸"];
+const BRANCHES = ["子", "丑", "寅", "卯", "辰", "巳", "午", "未", "申", "酉", "戌", "亥"];
+const MONTH_NAMES = ["", "正月", "二月", "三月", "四月", "五月", "六月", "七月", "八月", "九月", "十月", "冬月", "腊月"];
+const DAY_NAMES = [
+	"", "初一", "初二", "初三", "初四", "初五", "初六", "初七", "初八", "初九", "初十",
+	"十一", "十二", "十三", "十四", "十五", "十六", "十七", "十八", "十九", "二十",
+	"廿一", "廿二", "廿三", "廿四", "廿五", "廿六", "廿七", "廿八", "廿九", "三十"
+];
+
+// 1900 年至 2100 年的农历数据，每个数字描述一个农历年的闰月和大小月。
+const LUNAR_INFO = [
+	0x04bd8, 0x04ae0, 0x0a570, 0x054d5, 0x0d260, 0x0d950, 0x16554, 0x056a0, 0x09ad0, 0x055d2,
+	0x04ae0, 0x0a5b6, 0x0a4d0, 0x0d250, 0x1d255, 0x0b540, 0x0d6a0, 0x0ada2, 0x095b0, 0x14977,
+	0x04970, 0x0a4b0, 0x0b4b5, 0x06a50, 0x06d40, 0x1ab54, 0x02b60, 0x09570, 0x052f2, 0x04970,
+	0x06566, 0x0d4a0, 0x0ea50, 0x06e95, 0x05ad0, 0x02b60, 0x186e3, 0x092e0, 0x1c8d7, 0x0c950,
+	0x0d4a0, 0x1d8a6, 0x0b550, 0x056a0, 0x1a5b4, 0x025d0, 0x092d0, 0x0d2b2, 0x0a950, 0x0b557,
+	0x06ca0, 0x0b550, 0x15355, 0x04da0, 0x0a5d0, 0x14573, 0x052d0, 0x0a9a8, 0x0e950, 0x06aa0,
+	0x0aea6, 0x0ab50, 0x04b60, 0x0aae4, 0x0a570, 0x05260, 0x0f263, 0x0d950, 0x05b57, 0x056a0,
+	0x096d0, 0x04dd5, 0x04ad0, 0x0a4d0, 0x0d4d4, 0x0d250, 0x0d558, 0x0b540, 0x0b6a0, 0x195a6,
+	0x095b0, 0x049b0, 0x0a974, 0x0a4b0, 0x0b27a, 0x06a50, 0x06d40, 0x0af46, 0x0ab60, 0x09570,
+	0x04af5, 0x04970, 0x064b0, 0x074a3, 0x0ea50, 0x06b58, 0x055c0, 0x0ab60, 0x096d5, 0x092e0,
+	0x0c960, 0x0d954, 0x0d4a0, 0x0da50, 0x07552, 0x056a0, 0x0abb7, 0x025d0, 0x092d0, 0x0cab5,
+	0x0a950, 0x0b4a0, 0x0baa4, 0x0ad50, 0x055d9, 0x04ba0, 0x0a5b0, 0x15176, 0x052b0, 0x0a930,
+	0x07954, 0x06aa0, 0x0ad50, 0x05b52, 0x04b60, 0x0a6e6, 0x0a4e0, 0x0d260, 0x0ea65, 0x0d530,
+	0x05aa0, 0x076a3, 0x096d0, 0x04afb, 0x04ad0, 0x0a4d0, 0x1d0b6, 0x0d250, 0x0d520, 0x0dd45,
+	0x0b5a0, 0x056d0, 0x055b2, 0x049b0, 0x0a577, 0x0a4b0, 0x0aa50, 0x1b255, 0x06d20, 0x0ada0,
+	0x14b63, 0x09370, 0x049f8, 0x04970, 0x064b0, 0x168a6, 0x0ea50, 0x06b20, 0x1a6c4, 0x0aae0,
+	0x0a2e0, 0x0d2e3, 0x0c960, 0x0d557, 0x0d4a0, 0x0da50, 0x05d55, 0x056a0, 0x0a6d0, 0x055d4,
+	0x052d0, 0x0a9b8, 0x0a950, 0x0b4a0, 0x0b6a6, 0x0ad50, 0x055a0, 0x0aba4, 0x0a5b0, 0x052b0,
+	0x0b273, 0x06930, 0x07337, 0x06aa0, 0x0ad50, 0x14b55, 0x04b60, 0x0a570, 0x054e4, 0x0d160,
+	0x0e968, 0x0d520, 0x0daa0, 0x16aa6, 0x056d0, 0x04ae0, 0x0a9d4, 0x0a2d0, 0x0d150, 0x0f252,
+	0x0d520
+];
+
+export class LunarCalendar {
+	static readonly startYear = START_YEAR;
+	static readonly endYear = START_YEAR + LUNAR_INFO.length - 1;
+
+	static solarToLunar(dateValue: string | Date): LunarDate | undefined {
+		const date = this.parseSolarDate(dateValue);
+		if (!date || !this.isSupportedSolarDate(date)) {
+			return undefined;
+		}
+
+		let offset = Math.floor((Date.UTC(date.year, date.month - 1, date.day) - START_DATE) / DAY_MS);
+		let year = START_YEAR;
+		while (year <= this.endYear && offset >= this.yearDays(year)) {
+			offset -= this.yearDays(year);
+			year++;
+		}
+		if (year > this.endYear) {
+			return undefined;
+		}
+
+		const leapMonth = this.leapMonth(year);
+		let month = 1;
+		let isLeap = false;
+		while (month <= 12) {
+			const days = isLeap ? this.leapDays(year) : this.monthDays(year, month);
+			if (offset < days) {
+				break;
+			}
+			offset -= days;
+			if (leapMonth === month && !isLeap) {
+				isLeap = true;
+			} else {
+				isLeap = false;
+				month++;
+			}
+		}
+		return month > 12 ? undefined : { year, month, day: offset + 1, isLeap };
+	}
+
+	static lunarToSolar(lunarDate: LunarDate): string | undefined {
+		if (!this.isValidLunarDate(lunarDate)) {
+			return undefined;
+		}
+
+		let offset = 0;
+		for (let year = START_YEAR; year < lunarDate.year; year++) {
+			offset += this.yearDays(year);
+		}
+		const leapMonth = this.leapMonth(lunarDate.year);
+		for (let month = 1; month < lunarDate.month; month++) {
+			offset += this.monthDays(lunarDate.year, month);
+			if (month === leapMonth) {
+				offset += this.leapDays(lunarDate.year);
+			}
+		}
+		if (lunarDate.isLeap) {
+			offset += this.monthDays(lunarDate.year, lunarDate.month);
+		}
+		offset += lunarDate.day - 1;
+		const date = new Date(START_DATE + offset * DAY_MS);
+		return this.formatSolarDate({
+			year: date.getUTCFullYear(),
+			month: date.getUTCMonth() + 1,
+			day: date.getUTCDate()
+		});
+	}
+
+	static formatLunarDate(lunarDate: LunarDate): string {
+		const leapText = lunarDate.isLeap ? "闰" : "";
+		return `${this.getYearLabel(lunarDate.year)} ${leapText}${MONTH_NAMES[lunarDate.month]} ${DAY_NAMES[lunarDate.day]}`;
+	}
+
+	static getYearLabel(year: number): string {
+		const stemIndex = this.mod(year - 4, STEMS.length);
+		const branchIndex = this.mod(year - 4, BRANCHES.length);
+		return `${STEMS[stemIndex]}${BRANCHES[branchIndex]}年(${year})`;
+	}
+
+	static getMonthOptions(year: number): Array<{ value: string; month: number; isLeap: boolean; label: string }> {
+		if (!this.isSupportedLunarYear(year)) {
+			return [];
+		}
+		const options: Array<{ value: string; month: number; isLeap: boolean; label: string }> = [];
+		const leapMonth = this.leapMonth(year);
+		for (let month = 1; month <= 12; month++) {
+			options.push({ value: `${month}`, month, isLeap: false, label: MONTH_NAMES[month] });
+			if (month === leapMonth) {
+				options.push({ value: `${month}-leap`, month, isLeap: true, label: `闰${MONTH_NAMES[month]}` });
+			}
+		}
+		return options;
+	}
+
+	static getYearOptions(maxDate: string): Array<{ value: string; label: string }> {
+		const lunarDate = this.solarToLunar(maxDate) ?? { year: this.endYear, month: 12, day: 30, isLeap: false };
+		return Array.from({ length: lunarDate.year - START_YEAR + 1 }, (_, index) => {
+			const year = START_YEAR + index;
+			return { value: `${year}`, label: this.getYearLabel(year) };
+		});
+	}
+
+	static getMonthDays(lunarDate: Pick<LunarDate, "year" | "month" | "isLeap">): number {
+		return lunarDate.isLeap ? this.leapDays(lunarDate.year) : this.monthDays(lunarDate.year, lunarDate.month);
+	}
+
+	static isValidLunarDate(lunarDate: LunarDate): boolean {
+		if (!this.isSupportedLunarYear(lunarDate.year) || lunarDate.month < 1 || 12 < lunarDate.month) {
+			return false;
+		}
+		const leapMonth = this.leapMonth(lunarDate.year);
+		if (lunarDate.isLeap && leapMonth !== lunarDate.month) {
+			return false;
+		}
+		return 1 <= lunarDate.day && lunarDate.day <= this.getMonthDays(lunarDate);
+	}
+
+	static formatSolarDate(date: { year: number; month: number; day: number }): string {
+		return `${date.year.toString().padStart(4, "0")}-${date.month.toString().padStart(2, "0")}-${date.day.toString().padStart(2, "0")}`;
+	}
+
+	static today(): string {
+		const date = new Date();
+		return this.formatSolarDate({ year: date.getFullYear(), month: date.getMonth() + 1, day: date.getDate() });
+	}
+
+	private static parseSolarDate(value: string | Date): { year: number; month: number; day: number } | undefined {
+		if (value instanceof Date) {
+			return { year: value.getFullYear(), month: value.getMonth() + 1, day: value.getDate() };
+		}
+		const match = /^(\d{4})-(\d{2})-(\d{2})$/.exec(value);
+		if (!match) {
+			return undefined;
+		}
+		const year = Number(match[1]);
+		const month = Number(match[2]);
+		const day = Number(match[3]);
+		const date = new Date(Date.UTC(year, month - 1, day));
+		return date.getUTCFullYear() === year && date.getUTCMonth() + 1 === month && date.getUTCDate() === day
+			? { year, month, day }
+			: undefined;
+	}
+
+	private static isSupportedSolarDate(date: { year: number; month: number; day: number }): boolean {
+		return date.year >= START_YEAR && date.year <= this.endYear;
+	}
+
+	private static isSupportedLunarYear(year: number): boolean {
+		return year >= START_YEAR && year <= this.endYear;
+	}
+
+	private static leapMonth(year: number): number {
+		return LUNAR_INFO[year - START_YEAR] & 0xf;
+	}
+
+	private static leapDays(year: number): number {
+		return this.leapMonth(year) === 0 ? 0 : ((LUNAR_INFO[year - START_YEAR] & 0x10000) !== 0 ? 30 : 29);
+	}
+
+	private static monthDays(year: number, month: number): number {
+		return (LUNAR_INFO[year - START_YEAR] & (0x10000 >> month)) !== 0 ? 30 : 29;
+	}
+
+	private static yearDays(year: number): number {
+		let days = 348;
+		const info = LUNAR_INFO[year - START_YEAR];
+		for (let mask = 0x8000; mask > 0x8; mask >>= 1) {
+			if ((info & mask) !== 0) {
+				days++;
+			}
+		}
+		return days + this.leapDays(year);
+	}
+
+	private static mod(value: number, divisor: number): number {
+		return ((value % divisor) + divisor) % divisor;
+	}
+}