fix(dashboard): unify timezone handling

src/actions/statistics.ts

@@ -24,6 +24,11 @@ import type { ActionResult } from "./types";
  */
 const createDataKey = (prefix: string, id: number): string => `${prefix}-${id}`;
 
+function serializeChartBucketDate(value: string | Date): string {
+  const date = value instanceof Date ? value : new Date(value);
+  return Number.isNaN(date.getTime()) ? String(value) : date.toISOString();
+}
+
 /**
  * 获取用户统计数据，用于图表展示
  */
@@ -99,16 +104,7 @@ export async function getUserStatistics(
     const dataByDate = new Map<string, ChartDataItem>();
 
     statsData.forEach((row) => {
-      // 根据分辨率格式化日期
-      let dateStr: string;
-      if (rangeConfig.resolution === "hour") {
-        // 小时分辨率：显示为 "HH:mm" 格式
-        const hour = new Date(row.date);
-        dateStr = hour.toISOString();
-      } else {
-        // 天分辨率：显示为 "YYYY-MM-DD" 格式
-        dateStr = new Date(row.date).toISOString().split("T")[0];
-      }
+      const dateStr = serializeChartBucketDate(row.date);
 
       if (!dataByDate.has(dateStr)) {
         dataByDate.set(dateStr, {

src/actions/system-config.ts

@@ -8,6 +8,11 @@ import { invalidateSystemSettingsCache } from "@/lib/config";
 import { logger } from "@/lib/logger";
 import { publishCurrentPublicStatusConfigProjection } from "@/lib/public-status/config-publisher";
 import { schedulePublicStatusRebuild } from "@/lib/public-status/rebuild-hints";
+import {
+  invalidateAllLeaderboardCaches,
+  invalidateAllOverviewCaches,
+  invalidateAllStatisticsCaches,
+} from "@/lib/redis";
 import { resolveSystemTimezone } from "@/lib/utils/timezone";
 import { UpdateSystemSettingsSchema } from "@/lib/validation/schemas";
 import { getSystemSettings, updateSystemSettings } from "@/repository/system-config";
@@ -151,6 +156,18 @@ export async function saveSystemSettings(formData: {
     );
     invalidateProviderSelectorSystemSettingsCache();
 
+    if (validated.timezone !== undefined) {
+      await Promise.all([
+        invalidateAllOverviewCaches(),
+        invalidateAllStatisticsCaches(),
+        invalidateAllLeaderboardCaches(),
+      ]).catch((error) => {
+        logger.warn("[SystemSettings] Failed to invalidate timezone-sensitive dashboard caches", {
+          error,
+        });
+      });
+    }
+
     const shouldRepublishPublicStatusProjection =
       validated.siteTitle !== undefined ||
       validated.timezone !== undefined ||

src/app/[locale]/dashboard/leaderboard/_components/date-range-picker.tsx

@@ -1,8 +1,9 @@
 "use client";
 
 import { addDays, endOfMonth, endOfWeek, format, startOfMonth, startOfWeek } from "date-fns";
+import { formatInTimeZone, toZonedTime } from "date-fns-tz";
 import { CalendarIcon, ChevronLeft, ChevronRight } from "lucide-react";
-import { useTranslations } from "next-intl";
+import { useTimeZone, useTranslations } from "next-intl";
 import { useCallback, useMemo, useState } from "react";
 import type { DateRange } from "react-day-picker";
 import { Button } from "@/components/ui/button";
@@ -28,6 +29,10 @@ function formatDate(date: Date): string {
   return format(date, "yyyy-MM-dd");
 }
 
+function formatDateInSystemTimeZone(date: Date, timeZone: string): string {
+  return formatInTimeZone(date, timeZone, "yyyy-MM-dd");
+}
+
 function parseDate(dateStr: string): Date {
   // Parse as local date to avoid timezone issues
   // new Date("YYYY-MM-DD") parses as UTC, which causes off-by-one errors in different timezones
@@ -37,8 +42,10 @@ function parseDate(dateStr: string): Date {
 
 function getDateRangeForPeriod(
   period: QuickPeriod,
-  baseDate: Date = new Date()
+  timeZone: string,
+  now: Date = new Date()
 ): { startDate: string; endDate: string } {
+  const baseDate = toZonedTime(now, timeZone);
   switch (period) {
     case "daily":
       return { startDate: formatDate(baseDate), endDate: formatDate(baseDate) };
@@ -53,7 +60,7 @@ function getDateRangeForPeriod(
       return { startDate: formatDate(start), endDate: formatDate(end) };
     }
     default:
-      return { startDate: "2020-01-01", endDate: formatDate(new Date()) };
+      return { startDate: "2020-01-01", endDate: formatDateInSystemTimeZone(now, timeZone) };
   }
 }
 
@@ -74,17 +81,19 @@ function shiftDateRange(
 
 export function DateRangePicker({ period, dateRange, onPeriodChange }: DateRangePickerProps) {
   const t = useTranslations("dashboard.leaderboard");
+  const timeZone = useTimeZone() ?? "UTC";
   const [calendarOpen, setCalendarOpen] = useState(false);
+  const today = useMemo(() => formatDateInSystemTimeZone(new Date(), timeZone), [timeZone]);
 
   const currentRange = useMemo(() => {
     if (period === "custom" && dateRange) {
       return dateRange;
     }
     if (period !== "custom" && QUICK_PERIODS.includes(period as QuickPeriod)) {
-      return getDateRangeForPeriod(period as QuickPeriod);
+      return getDateRangeForPeriod(period as QuickPeriod, timeZone);
     }
-    return getDateRangeForPeriod("daily");
-  }, [period, dateRange]);
+    return getDateRangeForPeriod("daily", timeZone);
+  }, [period, dateRange, timeZone]);
 
   const selectedRange: DateRange = useMemo(() => {
     return {
@@ -198,7 +207,7 @@ export function DateRangePicker({ period, dateRange, onPeriodChange }: DateRange
               selected={selectedRange}
               onSelect={handleDateRangeSelect}
               numberOfMonths={2}
-              disabled={{ after: new Date() }}
+              disabled={{ after: parseDate(today) }}
             />
           </PopoverContent>
         </Popover>
@@ -207,7 +216,7 @@ export function DateRangePicker({ period, dateRange, onPeriodChange }: DateRange
           variant="outline"
           size="icon-sm"
           onClick={() => handleNavigate("next")}
-          disabled={period === "allTime" || currentRange.endDate >= formatDate(new Date())}
+          disabled={period === "allTime" || currentRange.endDate >= today}
           title={t("dateRange.nextPeriod")}
         >
           <ChevronRight className="h-4 w-4" />

src/app/[locale]/dashboard/leaderboard/user/[userId]/_components/filters/types.ts

@@ -1,3 +1,6 @@
+import { format, subDays } from "date-fns";
+import { toZonedTime } from "date-fns-tz";
+
 export type TimeRangePreset = "today" | "7days" | "30days" | "thisMonth";
 
 export interface UserInsightsFilters {
@@ -17,33 +20,38 @@ export const DEFAULT_FILTERS: UserInsightsFilters = {
 export function resolveTimePresetDates(preset: TimeRangePreset): {
   startDate?: string;
   endDate?: string;
+};
+export function resolveTimePresetDates(
+  preset: TimeRangePreset,
+  timeZone: string | undefined,
+  now?: Date
+): {
+  startDate?: string;
+  endDate?: string;
+};
+export function resolveTimePresetDates(
+  preset: TimeRangePreset,
+  timeZone?: string,
+  now: Date = new Date()
+): {
+  startDate?: string;
+  endDate?: string;
 } {
-  const now = new Date();
-  const yyyy = now.getFullYear();
-  const mm = String(now.getMonth() + 1).padStart(2, "0");
-  const dd = String(now.getDate()).padStart(2, "0");
-  const today = `${yyyy}-${mm}-${dd}`;
+  const baseDate = timeZone ? toZonedTime(now, timeZone) : now;
+  const today = format(baseDate, "yyyy-MM-dd");
 
   switch (preset) {
     case "today":
       return { startDate: today, endDate: today };
     case "7days": {
-      const start = new Date(now);
-      start.setDate(start.getDate() - 6);
-      const sy = start.getFullYear();
-      const sm = String(start.getMonth() + 1).padStart(2, "0");
-      const sd = String(start.getDate()).padStart(2, "0");
-      return { startDate: `${sy}-${sm}-${sd}`, endDate: today };
+      const start = subDays(baseDate, 6);
+      return { startDate: format(start, "yyyy-MM-dd"), endDate: today };
     }
     case "30days": {
-      const start = new Date(now);
-      start.setDate(start.getDate() - 29);
-      const sy = start.getFullYear();
-      const sm = String(start.getMonth() + 1).padStart(2, "0");
-      const sd = String(start.getDate()).padStart(2, "0");
-      return { startDate: `${sy}-${sm}-${sd}`, endDate: today };
+      const start = subDays(baseDate, 29);
+      return { startDate: format(start, "yyyy-MM-dd"), endDate: today };
     }
     case "thisMonth":
-      return { startDate: `${yyyy}-${mm}-01`, endDate: today };
+      return { startDate: format(baseDate, "yyyy-MM-01"), endDate: today };
   }
 }

src/app/[locale]/dashboard/leaderboard/user/[userId]/_components/user-insights-view.tsx

@@ -1,7 +1,7 @@
 "use client";
 
 import { ArrowLeft } from "lucide-react";
-import { useTranslations } from "next-intl";
+import { useTimeZone, useTranslations } from "next-intl";
 import { useState } from "react";
 import { Button } from "@/components/ui/button";
 import { useRouter } from "@/i18n/routing";
@@ -19,10 +19,11 @@ interface UserInsightsViewProps {
 
 export function UserInsightsView({ userId, userName }: UserInsightsViewProps) {
   const t = useTranslations("dashboard.leaderboard.userInsights");
+  const timeZone = useTimeZone() ?? "UTC";
   const router = useRouter();
   const [filters, setFilters] = useState<UserInsightsFilters>(DEFAULT_FILTERS);
 
-  const { startDate, endDate } = resolveTimePresetDates(filters.timeRange);
+  const { startDate, endDate } = resolveTimePresetDates(filters.timeRange, timeZone);
 
   return (
     <div className="space-y-6" data-testid="user-insights-page">

src/app/[locale]/dashboard/logs/_components/filters/active-filters-display.tsx

@@ -1,6 +1,7 @@
 "use client";
 
 import { format } from "date-fns";
+import { formatInTimeZone } from "date-fns-tz";
 import { X } from "lucide-react";
 import { useTranslations } from "next-intl";
 import { useMemo } from "react";
@@ -15,6 +16,7 @@ interface ActiveFiltersDisplayProps {
   onClearAll: () => void;
   displayNames: FilterDisplayNames;
   isAdmin: boolean;
+  serverTimeZone?: string;
   className?: string;
 }
 
@@ -30,6 +32,7 @@ export function ActiveFiltersDisplay({
   onClearAll,
   displayNames,
   isAdmin,
+  serverTimeZone,
   className,
 }: ActiveFiltersDisplayProps) {
   const t = useTranslations("dashboard.logs.filters");
@@ -81,8 +84,12 @@ export function ActiveFiltersDisplay({
 
     // Date range filter
     if (filters.startTime && filters.endTime) {
-      const startDate = format(new Date(filters.startTime), "MM/dd");
-      const endDate = format(new Date(filters.endTime - 1000), "MM/dd");
+      const startDate = serverTimeZone
+        ? formatInTimeZone(new Date(filters.startTime), serverTimeZone, "MM/dd")
+        : format(new Date(filters.startTime), "MM/dd");
+      const endDate = serverTimeZone
+        ? formatInTimeZone(new Date(filters.endTime - 1000), serverTimeZone, "MM/dd")
+        : format(new Date(filters.endTime - 1000), "MM/dd");
       result.push({
         key: "startTime",
         label: t("dateRange"),
@@ -133,7 +140,7 @@ export function ActiveFiltersDisplay({
     }
 
     return result;
-  }, [filters, displayNames, isAdmin, t]);
+  }, [filters, displayNames, isAdmin, serverTimeZone, t]);
 
   if (activeFilters.length === 0) {
     return null;

src/app/[locale]/dashboard/logs/_components/logs-date-range-picker.tsx

@@ -87,6 +87,10 @@ export function LogsDateRangePicker({
   const [calendarOpen, setCalendarOpen] = useState(false);
 
   const hasDateRange = Boolean(startDate && endDate);
+  const today = useMemo(
+    () => getDateRangeForPeriod("today", serverTimeZone).endDate,
+    [serverTimeZone]
+  );
 
   const activeQuickPeriod = useMemo(() => {
     return detectQuickPeriod(startDate, endDate, serverTimeZone);
@@ -212,7 +216,7 @@ export function LogsDateRangePicker({
               selected={selectedRange}
               onSelect={handleDateRangeSelect}
               numberOfMonths={2}
-              disabled={{ after: new Date() }}
+              disabled={{ after: parseDate(today) }}
             />
             {hasDateRange && (
               <div className="border-t p-2">
@@ -228,7 +232,7 @@ export function LogsDateRangePicker({
           variant="outline"
           size="icon-sm"
           onClick={() => handleNavigate("next")}
-          disabled={!hasDateRange || (endDate !== undefined && endDate >= formatDate(new Date()))}
+          disabled={!hasDateRange || (endDate !== undefined && endDate >= today)}
           title={t("leaderboard.dateRange.nextPeriod")}
         >
           <ChevronRight className="h-4 w-4" />

src/app/[locale]/dashboard/logs/_components/usage-logs-filters.tsx

@@ -350,6 +350,7 @@ export function UsageLogsFilters({
         onClearAll={handleReset}
         displayNames={displayNames}
         isAdmin={isAdmin}
+        serverTimeZone={serverTimeZone}
       />
 
       {/* Filter Sections */}

src/app/[locale]/dashboard/logs/_components/usage-logs-view-virtualized.tsx

@@ -379,6 +379,7 @@ function UsageLogsViewContent({
             autoRefreshEnabled={!isFullscreenOpen && isAutoRefresh}
             autoRefreshIntervalMs={logsRefreshIntervalMs ?? 5000}
             hiddenColumns={hiddenColumns}
+            serverTimeZone={serverTimeZone}
           />
         </div>
       </div>
@@ -469,6 +470,7 @@ function UsageLogsViewContent({
               hideScrollToTop={true}
               hiddenColumns={hideProviderColumn ? ["provider"] : undefined}
               bodyClassName="h-[calc(var(--cch-viewport-height,100vh)_-_56px_-_32px_-_40px)]"
+              serverTimeZone={serverTimeZone}
             />
           </div>
         </div>

src/app/[locale]/dashboard/logs/_components/virtualized-logs-table.tsx

@@ -124,7 +124,7 @@ export function VirtualizedLogsTable({
   hideScrollToTop = false,
   hiddenColumns,
   bodyClassName,
-  serverTimeZone: _serverTimeZone,
+  serverTimeZone,
   fetchFn,
   queryKeyPrefix = "usage-logs-batch",
   disableDetailDialog = false,
@@ -717,7 +717,12 @@ export function VirtualizedLogsTable({
                   >
                     {/* Time */}
                     <div className="flex-[0.6] min-w-[56px] font-mono text-xs truncate pl-3">
-                      <RelativeTime date={log.createdAt} fallback="-" format="short" />
+                      <RelativeTime
+                        date={log.createdAt}
+                        fallback="-"
+                        format="short"
+                        timeZone={serverTimeZone}
+                      />
                     </div>
 
                     {/* User */}