's'

app/lib/dates.ts

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+/** 中国星期名称 */
+const WEEKDAY_CN = ["周日", "周一", "周二", "周三", "周四", "周五", "周六"] as const;
+
+/** 中国时区 */
+const TZ = "Asia/Shanghai";
+
+/**
+ * 获取中国时区下的日期数字（月、日、星期）
+ */
+function getChinaDateParts(): { year: number; month: number; day: number; weekday: number } {
+  const now = new Date();
+  const formatter = new Intl.DateTimeFormat("en-CA", {
+    timeZone: TZ,
+    year: "numeric",
+    month: "numeric",
+    day: "numeric",
+    weekday: "short",
+  });
+  const parts = formatter.formatToParts(now);
+  const get = (type: string) => parseInt(parts.find((p) => p.type === type)?.value ?? "0", 10);
+  const weekdayStr = parts.find((p) => p.type === "weekday")?.value ?? "Sun";
+  const weekdayMap: Record<string, number> = { Sun: 0, Mon: 1, Tue: 2, Wed: 3, Thu: 4, Fri: 5, Sat: 6 };
+  return {
+    year: get("year"),
+    month: get("month"),
+    day: get("day"),
+    weekday: weekdayMap[weekdayStr] ?? 0,
+  };
+}
+
+/**
+ * 格式化为中文日期：M月D日 周X
+ */
+function formatDateCN(month: number, day: number, weekday: number): string {
+  return `${month}月${day}日 ${WEEKDAY_CN[weekday]}`;
+}
+
+/**
+ * 获取下一个周六、周日的日期（中国日历）
+ * session-1 对应周六，session-2 对应周日
+ */
+export function getNextWeekendDates(): { saturday: string; sunday: string } {
+  const { year, month, day, weekday } = getChinaDateParts();
+
+  let satM = month;
+  let satD = day;
+  let satW = 6;
+  let sunM = month;
+  let sunD = day;
+  let sunW = 0;
+
+  if (weekday === 0) {
+    // 今天周日：下周六 +6 天，下周日 +7 天
+    const d = new Date(year, month - 1, day);
+    d.setDate(d.getDate() + 6);
+    satM = d.getMonth() + 1;
+    satD = d.getDate();
+    d.setDate(d.getDate() + 1);
+    sunM = d.getMonth() + 1;
+    sunD = d.getDate();
+  } else if (weekday === 6) {
+    // 今天周六：明天周日
+    const d = new Date(year, month - 1, day);
+    d.setDate(d.getDate() + 1);
+    sunM = d.getMonth() + 1;
+    sunD = d.getDate();
+  } else {
+    // 周一至周五
+    const daysToSat = 6 - weekday;
+    const d = new Date(year, month - 1, day);
+    d.setDate(d.getDate() + daysToSat);
+    satM = d.getMonth() + 1;
+    satD = d.getDate();
+    d.setDate(d.getDate() + 1);
+    sunM = d.getMonth() + 1;
+    sunD = d.getDate();
+  }
+
+  return {
+    saturday: formatDateCN(satM, satD, 6),
+    sunday: formatDateCN(sunM, sunD, 0),
+  };
+}