Fix email timing and show fallback data when Garmin sync pending

- Add 15-minute notification granularity (*/15 cron) so users get emails
  at their configured time instead of rounding to the nearest hour
- Add DailyLog fallback to most recent when today's log doesn't exist,
  preventing 100/100/Unknown default values before morning sync
- Show "Last synced" indicator when displaying stale data
- Change Garmin sync to 6-hour intervals (0,6,12,18 UTC) to ensure
  data is available before European morning notifications

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/app/api/cron/notifications/route.test.ts

@@ -205,6 +205,112 @@ describe("POST /api/cron/notifications", () => {
     });
   });
 
+  describe("Quarter-hour time matching", () => {
+    it("sends notification at exact 15-minute slot (07:15)", async () => {
+      // Current time is 07:15 UTC
+      vi.setSystemTime(new Date("2025-01-15T07:15:00Z"));
+      mockUsers = [
+        createMockUser({ notificationTime: "07:15", timezone: "UTC" }),
+      ];
+      mockDailyLogs = [createMockDailyLog()];
+
+      const response = await POST(createMockRequest(`Bearer ${validSecret}`));
+
+      expect(response.status).toBe(200);
+      expect(mockSendDailyEmail).toHaveBeenCalled();
+    });
+
+    it("rounds down notification time to nearest 15-minute slot (07:10 -> 07:00)", async () => {
+      // Current time is 07:00 UTC
+      vi.setSystemTime(new Date("2025-01-15T07:00:00Z"));
+      // User set 07:10, which rounds down to 07:00 slot
+      mockUsers = [
+        createMockUser({ notificationTime: "07:10", timezone: "UTC" }),
+      ];
+      mockDailyLogs = [createMockDailyLog()];
+
+      const response = await POST(createMockRequest(`Bearer ${validSecret}`));
+
+      expect(response.status).toBe(200);
+      expect(mockSendDailyEmail).toHaveBeenCalled();
+    });
+
+    it("rounds down notification time (07:29 -> 07:15)", async () => {
+      // Current time is 07:15 UTC
+      vi.setSystemTime(new Date("2025-01-15T07:15:00Z"));
+      // User set 07:29, which rounds down to 07:15 slot
+      mockUsers = [
+        createMockUser({ notificationTime: "07:29", timezone: "UTC" }),
+      ];
+      mockDailyLogs = [createMockDailyLog()];
+
+      const response = await POST(createMockRequest(`Bearer ${validSecret}`));
+
+      expect(response.status).toBe(200);
+      expect(mockSendDailyEmail).toHaveBeenCalled();
+    });
+
+    it("does not send notification when minute slot does not match", async () => {
+      // Current time is 07:00 UTC
+      vi.setSystemTime(new Date("2025-01-15T07:00:00Z"));
+      // User wants 07:15, but current slot is 07:00
+      mockUsers = [
+        createMockUser({ notificationTime: "07:15", timezone: "UTC" }),
+      ];
+      mockDailyLogs = [createMockDailyLog()];
+
+      const response = await POST(createMockRequest(`Bearer ${validSecret}`));
+
+      expect(response.status).toBe(200);
+      expect(mockSendDailyEmail).not.toHaveBeenCalled();
+    });
+
+    it("handles 30-minute slot correctly", async () => {
+      // Current time is 07:30 UTC
+      vi.setSystemTime(new Date("2025-01-15T07:30:00Z"));
+      mockUsers = [
+        createMockUser({ notificationTime: "07:30", timezone: "UTC" }),
+      ];
+      mockDailyLogs = [createMockDailyLog()];
+
+      const response = await POST(createMockRequest(`Bearer ${validSecret}`));
+
+      expect(response.status).toBe(200);
+      expect(mockSendDailyEmail).toHaveBeenCalled();
+    });
+
+    it("handles 45-minute slot correctly", async () => {
+      // Current time is 07:45 UTC
+      vi.setSystemTime(new Date("2025-01-15T07:45:00Z"));
+      mockUsers = [
+        createMockUser({ notificationTime: "07:45", timezone: "UTC" }),
+      ];
+      mockDailyLogs = [createMockDailyLog()];
+
+      const response = await POST(createMockRequest(`Bearer ${validSecret}`));
+
+      expect(response.status).toBe(200);
+      expect(mockSendDailyEmail).toHaveBeenCalled();
+    });
+
+    it("handles timezone with 15-minute matching", async () => {
+      // Current time is 07:15 UTC = 02:15 America/New_York (EST is UTC-5)
+      vi.setSystemTime(new Date("2025-01-15T07:15:00Z"));
+      mockUsers = [
+        createMockUser({
+          notificationTime: "02:15",
+          timezone: "America/New_York",
+        }),
+      ];
+      mockDailyLogs = [createMockDailyLog()];
+
+      const response = await POST(createMockRequest(`Bearer ${validSecret}`));
+
+      expect(response.status).toBe(200);
+      expect(mockSendDailyEmail).toHaveBeenCalled();
+    });
+  });
+
   describe("DailyLog handling", () => {
     it("does not send notification if no DailyLog exists for today", async () => {
       mockUsers = [

src/app/api/cron/notifications/route.ts

@@ -17,19 +17,40 @@ interface NotificationResult {
   timestamp: string;
 }
 
-// Get the current hour in a specific timezone
-function getCurrentHourInTimezone(timezone: string): number {
+// Get current quarter-hour slot (0, 15, 30, 45) in user's timezone
+function getCurrentQuarterHourSlot(timezone: string): {
+  hour: number;
+  minute: number;
+} {
   const formatter = new Intl.DateTimeFormat("en-US", {
     timeZone: timezone,
     hour: "numeric",
+    minute: "numeric",
     hour12: false,
   });
-  return parseInt(formatter.format(new Date()), 10);
+  const parts = formatter.formatToParts(new Date());
+  const hour = Number.parseInt(
+    parts.find((p) => p.type === "hour")?.value ?? "0",
+    10,
+  );
+  const minute = Number.parseInt(
+    parts.find((p) => p.type === "minute")?.value ?? "0",
+    10,
+  );
+  // Round down to nearest 15-min slot
+  const slot = Math.floor(minute / 15) * 15;
+  return { hour, minute: slot };
 }
 
-// Extract hour from "HH:MM" format
-function getNotificationHour(notificationTime: string): number {
-  return parseInt(notificationTime.split(":")[0], 10);
+// Extract quarter-hour slot from "HH:MM" format
+function getNotificationSlot(notificationTime: string): {
+  hour: number;
+  minute: number;
+} {
+  const [h, m] = notificationTime.split(":").map(Number);
+  // Round down to nearest 15-min slot
+  const slot = Math.floor(m / 15) * 15;
+  return { hour: h, minute: slot };
 }
 
 // Map decision status to icon
@@ -95,11 +116,14 @@ export async function POST(request: Request) {
 
   for (const user of users) {
     try {
-      // Check if current hour in user's timezone matches their notification time
-      const currentHour = getCurrentHourInTimezone(user.timezone);
-      const notificationHour = getNotificationHour(user.notificationTime);
+      // Check if current quarter-hour slot in user's timezone matches their notification time
+      const currentSlot = getCurrentQuarterHourSlot(user.timezone);
+      const notificationSlot = getNotificationSlot(user.notificationTime);
 
-      if (currentHour !== notificationHour) {
+      if (
+        currentSlot.hour !== notificationSlot.hour ||
+        currentSlot.minute !== notificationSlot.minute
+      ) {
         result.skippedWrongTime++;
         continue;
       }

src/app/api/today/route.test.ts

@@ -9,9 +9,12 @@ import type { DailyLog, User } from "@/types";
 // Module-level variable to control mock user in tests
 let currentMockUser: User | null = null;
 
-// Module-level variable to control mock daily log in tests
+// Module-level variable to control mock daily log for today in tests
 let currentMockDailyLog: DailyLog | null = null;
 
+// Module-level variable to control mock daily log for fallback (most recent)
+let fallbackMockDailyLog: DailyLog | null = null;
+
 // Track the filter string passed to getFirstListItem
 let lastDailyLogFilter: string | null = null;
 
@@ -37,13 +40,33 @@ const mockPb = {
       // Capture the filter for testing
       if (collectionName === "dailyLogs") {
         lastDailyLogFilter = filter;
-      }
+
+        // Check if this is a query for today's log (has date range filter)
+        const isTodayQuery =
+          filter.includes("date>=") && filter.includes("date<");
+        if (isTodayQuery) {
           if (!currentMockDailyLog) {
-        const error = new Error("No DailyLog found");
+            const error = new Error("No DailyLog found for today");
             (error as { status?: number }).status = 404;
             throw error;
           }
           return currentMockDailyLog;
+        }
+
+        // This is the fallback query for most recent log
+        if (fallbackMockDailyLog) {
+          return fallbackMockDailyLog;
+        }
+        if (currentMockDailyLog) {
+          return currentMockDailyLog;
+        }
+        const error = new Error("No DailyLog found");
+        (error as { status?: number }).status = 404;
+        throw error;
+      }
+      const error = new Error("No DailyLog found");
+      (error as { status?: number }).status = 404;
+      throw error;
     }),
   })),
 };
@@ -112,6 +135,7 @@ describe("GET /api/today", () => {
     vi.clearAllMocks();
     currentMockUser = null;
     currentMockDailyLog = null;
+    fallbackMockDailyLog = null;
     lastDailyLogFilter = null;
     // Mock current date to 2025-01-10 for predictable testing
     vi.useFakeTimers();
@@ -592,4 +616,90 @@ describe("GET /api/today", () => {
       expect(body.decision.status).toBe("TRAIN");
     });
   });
+
+  describe("DailyLog fallback to most recent", () => {
+    it("returns lastSyncedAt as today when today's DailyLog exists", async () => {
+      currentMockUser = createMockUser();
+      currentMockDailyLog = createMockDailyLog();
+
+      const response = await GET(mockRequest);
+
+      expect(response.status).toBe(200);
+      const body = await response.json();
+
+      expect(body.lastSyncedAt).toBe("2025-01-10");
+    });
+
+    it("uses yesterday's DailyLog when today's does not exist", async () => {
+      currentMockUser = createMockUser();
+      currentMockDailyLog = null; // No today's log
+      // Yesterday's log with different biometrics
+      fallbackMockDailyLog = createMockDailyLog({
+        date: new Date("2025-01-09"),
+        hrvStatus: "Balanced",
+        bodyBatteryCurrent: 72,
+        bodyBatteryYesterdayLow: 38,
+        weekIntensityMinutes: 90,
+        phaseLimit: 150,
+      });
+
+      const response = await GET(mockRequest);
+
+      expect(response.status).toBe(200);
+      const body = await response.json();
+
+      // Should use fallback data
+      expect(body.biometrics.hrvStatus).toBe("Balanced");
+      expect(body.biometrics.bodyBatteryCurrent).toBe(72);
+      expect(body.biometrics.bodyBatteryYesterdayLow).toBe(38);
+      expect(body.biometrics.weekIntensityMinutes).toBe(90);
+    });
+
+    it("returns lastSyncedAt as yesterday's date when using fallback", async () => {
+      currentMockUser = createMockUser();
+      currentMockDailyLog = null;
+      fallbackMockDailyLog = createMockDailyLog({
+        date: new Date("2025-01-09"),
+      });
+
+      const response = await GET(mockRequest);
+
+      expect(response.status).toBe(200);
+      const body = await response.json();
+
+      expect(body.lastSyncedAt).toBe("2025-01-09");
+    });
+
+    it("returns null lastSyncedAt when no logs exist at all", async () => {
+      currentMockUser = createMockUser();
+      currentMockDailyLog = null;
+      fallbackMockDailyLog = null;
+
+      const response = await GET(mockRequest);
+
+      expect(response.status).toBe(200);
+      const body = await response.json();
+
+      expect(body.lastSyncedAt).toBeNull();
+      // Should use DEFAULT_BIOMETRICS
+      expect(body.biometrics.hrvStatus).toBe("Unknown");
+      expect(body.biometrics.bodyBatteryCurrent).toBe(100);
+      expect(body.biometrics.bodyBatteryYesterdayLow).toBe(100);
+    });
+
+    it("handles fallback log with string date format", async () => {
+      currentMockUser = createMockUser();
+      currentMockDailyLog = null;
+      fallbackMockDailyLog = createMockDailyLog({
+        date: "2025-01-08T10:00:00Z" as unknown as Date,
+      });
+
+      const response = await GET(mockRequest);
+
+      expect(response.status).toBe(200);
+      const body = await response.json();
+
+      expect(body.lastSyncedAt).toBe("2025-01-08");
+    });
+  });
 });

src/app/api/today/route.ts

@@ -72,18 +72,19 @@ export const GET = withAuth(async (_request, user, pb) => {
     daysUntilNextPhase = cycleLength - 6 - cycleDay;
   }
 
-  // Try to fetch today's DailyLog for biometrics
+  // Try to fetch today's DailyLog for biometrics, fall back to most recent
   // Sort by date DESC to get the most recent record if multiple exist
   let biometrics = { ...DEFAULT_BIOMETRICS, phaseLimit };
-  try {
+  let lastSyncedAt: string | null = null;
+
   // Use YYYY-MM-DD format with >= and < operators for PocketBase date field
-    // PocketBase accepts simple date strings in comparison operators
   const today = new Date().toISOString().split("T")[0];
-    const tomorrow = new Date(Date.now() + 86400000)
-      .toISOString()
-      .split("T")[0];
+  const tomorrow = new Date(Date.now() + 86400000).toISOString().split("T")[0];
 
   logger.info({ userId: user.id, today, tomorrow }, "Fetching dailyLog");
+
+  try {
+    // First try to get today's log
     const dailyLog = await pb
       .collection("dailyLogs")
       .getFirstListItem<DailyLog>(
@@ -98,7 +99,7 @@ export const GET = withAuth(async (_request, user, pb) => {
         hrvStatus: dailyLog.hrvStatus,
         bodyBatteryCurrent: dailyLog.bodyBatteryCurrent,
       },
-      "Found dailyLog",
+      "Found dailyLog for today",
     );
 
     biometrics = {
@@ -111,8 +112,51 @@ export const GET = withAuth(async (_request, user, pb) => {
       weekIntensityMinutes: dailyLog.weekIntensityMinutes,
       phaseLimit: dailyLog.phaseLimit,
     };
-  } catch (err) {
-    logger.warn({ userId: user.id, err }, "No dailyLog found, using defaults");
+    lastSyncedAt = today;
+  } catch {
+    // No today's log - try to get most recent
+    logger.info(
+      { userId: user.id },
+      "No dailyLog for today, trying most recent",
+    );
+    try {
+      const dailyLog = await pb
+        .collection("dailyLogs")
+        .getFirstListItem<DailyLog>(`user="${user.id}"`, { sort: "-date" });
+
+      // Extract date from the log for "last synced" indicator
+      const dateValue = dailyLog.date as unknown as string | Date;
+      lastSyncedAt =
+        typeof dateValue === "string"
+          ? dateValue.split("T")[0]
+          : dateValue.toISOString().split("T")[0];
+
+      logger.info(
+        {
+          userId: user.id,
+          dailyLogId: dailyLog.id,
+          lastSyncedAt,
+        },
+        "Using most recent dailyLog as fallback",
+      );
+
+      biometrics = {
+        hrvStatus: dailyLog.hrvStatus,
+        bodyBatteryCurrent:
+          dailyLog.bodyBatteryCurrent ?? DEFAULT_BIOMETRICS.bodyBatteryCurrent,
+        bodyBatteryYesterdayLow:
+          dailyLog.bodyBatteryYesterdayLow ??
+          DEFAULT_BIOMETRICS.bodyBatteryYesterdayLow,
+        weekIntensityMinutes: dailyLog.weekIntensityMinutes,
+        phaseLimit: dailyLog.phaseLimit,
+      };
+    } catch {
+      // No logs at all - truly new user
+      logger.warn(
+        { userId: user.id },
+        "No dailyLog found at all, using defaults",
+      );
+    }
   }
 
   // Build DailyData for decision engine
@@ -153,5 +197,6 @@ export const GET = withAuth(async (_request, user, pb) => {
     cycleLength,
     biometrics,
     nutrition,
+    lastSyncedAt,
   });
 });

src/components/dashboard/data-panel.test.tsx

@@ -222,4 +222,52 @@ describe("DataPanel", () => {
       expect(progressFill).toHaveClass("bg-green-500");
     });
   });
+
+  describe("Last synced indicator", () => {
+    it("does not show indicator when lastSyncedAt is today", () => {
+      // Mock today's date
+      const today = new Date().toISOString().split("T")[0];
+      render(<DataPanel {...baseProps} lastSyncedAt={today} />);
+
+      expect(screen.queryByText(/Last synced:/)).not.toBeInTheDocument();
+      expect(
+        screen.queryByText(/Waiting for first sync/),
+      ).not.toBeInTheDocument();
+    });
+
+    it("shows 'Last synced: yesterday' when data is from yesterday", () => {
+      // Get yesterday's date
+      const yesterday = new Date(Date.now() - 86400000)
+        .toISOString()
+        .split("T")[0];
+      render(<DataPanel {...baseProps} lastSyncedAt={yesterday} />);
+
+      expect(screen.getByText(/Last synced: yesterday/)).toBeInTheDocument();
+    });
+
+    it("shows 'Last synced: X days ago' when data is older", () => {
+      // Get date from 3 days ago
+      const threeDaysAgo = new Date(Date.now() - 3 * 86400000)
+        .toISOString()
+        .split("T")[0];
+      render(<DataPanel {...baseProps} lastSyncedAt={threeDaysAgo} />);
+
+      expect(screen.getByText(/Last synced: 3 days ago/)).toBeInTheDocument();
+    });
+
+    it("shows 'Waiting for first sync' when lastSyncedAt is null", () => {
+      render(<DataPanel {...baseProps} lastSyncedAt={null} />);
+
+      expect(screen.getByText(/Waiting for first sync/)).toBeInTheDocument();
+    });
+
+    it("does not show indicator when lastSyncedAt is undefined (backwards compatible)", () => {
+      render(<DataPanel {...baseProps} />);
+
+      expect(screen.queryByText(/Last synced:/)).not.toBeInTheDocument();
+      expect(
+        screen.queryByText(/Waiting for first sync/),
+      ).not.toBeInTheDocument();
+    });
+  });
 });

src/components/dashboard/data-panel.tsx

@@ -7,6 +7,26 @@ interface DataPanelProps {
   weekIntensity: number;
   phaseLimit: number;
   remainingMinutes: number;
+  lastSyncedAt?: string | null;
+}
+
+// Calculate relative time description from a date string (YYYY-MM-DD)
+function getRelativeTimeDescription(dateStr: string): string | null {
+  const today = new Date();
+  const todayStr = today.toISOString().split("T")[0];
+
+  if (dateStr === todayStr) {
+    return null; // Don't show indicator for today
+  }
+
+  const syncDate = new Date(dateStr);
+  const diffMs = today.getTime() - syncDate.getTime();
+  const diffDays = Math.floor(diffMs / (1000 * 60 * 60 * 24));
+
+  if (diffDays === 1) {
+    return "yesterday";
+  }
+  return `${diffDays} days ago`;
 }
 
 function getHrvColorClass(status: string): string {
@@ -37,11 +57,23 @@ export function DataPanel({
   weekIntensity,
   phaseLimit,
   remainingMinutes,
+  lastSyncedAt,
 }: DataPanelProps) {
   const intensityPercentage =
     phaseLimit > 0 ? (weekIntensity / phaseLimit) * 100 : 0;
   const displayPercentage = Math.min(intensityPercentage, 100);
 
+  // Determine what to show for sync status
+  let syncIndicator: string | null = null;
+  if (lastSyncedAt === null) {
+    syncIndicator = "Waiting for first sync";
+  } else if (lastSyncedAt !== undefined) {
+    const relativeTime = getRelativeTimeDescription(lastSyncedAt);
+    if (relativeTime) {
+      syncIndicator = `Last synced: ${relativeTime}`;
+    }
+  }
+
   return (
     <div className="rounded-lg border p-4">
       <h3 className="font-semibold mb-4">YOUR DATA</h3>
@@ -81,6 +113,11 @@ export function DataPanel({
             ? `Remaining: ${remainingMinutes} min`
             : `Goal exceeded by ${Math.abs(remainingMinutes)} min`}
         </li>
+        {syncIndicator && (
+          <li className="text-amber-600 dark:text-amber-400 text-xs pt-1">
+            {syncIndicator}
+          </li>
+        )}
       </ul>
     </div>
   );

src/instrumentation.ts

@@ -43,20 +43,21 @@ export async function register() {
       }
     }
 
-    // Schedule notifications at the top of every hour
-    cron.default.schedule("0 * * * *", () => {
+    // Schedule notifications every 15 minutes for finer-grained delivery times
+    cron.default.schedule("*/15 * * * *", () => {
       console.log("[cron] Triggering notifications...");
       triggerCronEndpoint("notifications", "Notifications");
     });
 
-    // Schedule Garmin sync 3 times daily (8 AM, 2 PM, 10 PM UTC)
-    cron.default.schedule("0 8,14,22 * * *", () => {
+    // Schedule Garmin sync 4 times daily (every 6 hours) to ensure data is available
+    // before European morning notifications
+    cron.default.schedule("0 0,6,12,18 * * *", () => {
       console.log("[cron] Triggering Garmin sync...");
       triggerCronEndpoint("garmin-sync", "Garmin sync");
     });
 
     console.log(
-      "[cron] Scheduler started - notifications hourly, Garmin sync at 08:00/14:00/22:00 UTC",
+      "[cron] Scheduler started - notifications every 15 min, Garmin sync at 00:00/06:00/12:00/18:00 UTC",
     );
   }
 }