修改

app/Service/LargeScreenService.php

@@ -764,6 +764,7 @@ class LargeScreenService extends Service
         }
         // 1) 按设备名 -> 按日期 (Y-m-d) 聚合最小/最大时间戳
         $byDeviceDay = [];
+        $todayFirstTs = [];
         $emergencyCount = [];
         $e_map = Equipment::where('del_time',0)->pluck('id','title')->toArray();
         $today_data = [];
@@ -809,6 +810,9 @@ class LargeScreenService extends Service
             }
 
             if ($ts >= $todayStart && $ts <= $todayEnd) {
+                if (!isset($todayFirstTs[$device]) || $ts < $todayFirstTs[$device]) {
+                    $todayFirstTs[$device] = $ts;
+                }
                 $today_data[] = $row;
             }
         }
@@ -858,6 +862,9 @@ class LargeScreenService extends Service
                 'last_week_emergency'  => $emergencyCount[$device]['last_week'] ?? 0,
                 'last_month_emergency' => $emergencyCount[$device]['last_month'] ?? 0,
                 'oee' => $oee[$device] ?? 0,
+                'today_start'          => isset($todayFirstTs[$device])
+                    ? date('Y-m-d H:i:s', $todayFirstTs[$device])
+                    : '',
             ], $tmp);
         }
         usort($result, function($a, $b) {