Add expected time to device status bar

server/app/routers/api_frames.py

@@ -244,6 +244,14 @@ def api_status(
         "device": {
             "last_seen": frame.last_seen or None,
             "overdue": bool(frame.last_seen and now - frame.last_seen > overdue_gap),
+            # When the device is next expected to check in, per the same
+            # sleep duration frame_config() actually hands it (see
+            # device.py's /frame/config) -- not the raw overdue_gap above,
+            # which is deliberately generous (OVERDUE_FACTOR) to avoid
+            # false alarms during quiet hours rather than a best guess.
+            "expected_next_checkin": (
+                frame.last_seen + quiet_hours.effective_refresh_interval_s(frame) if frame.last_seen else None
+            ),
             "firmware_version": frame.device_firmware_version or None,
             "firmware_available": frame.firmware_available_version or None,
             "battery": (

server/app/static/device_status_bar.js

@@ -18,6 +18,14 @@ function renderDeviceStatusBar(device) {
   }
   const now = Date.now() / 1000;
   const rows = [];
+  if (device.expected_next_checkin) {
+    const remaining = device.expected_next_checkin - now;
+    rows.push([
+      'Expected in',
+      remaining > 0 ? `~${formatDuration(remaining)}` : 'Any moment',
+      device.overdue,
+    ]);
+  }
   const ago = formatDuration(Math.max(0, now - device.last_seen));
   rows.push(['Last seen', `${ago} ago`, device.overdue]);
   if (device.firmware_version) {