feat: accept the ndt7 server timestamp on measurements

src/common/mock-objects.ts

@@ -635,6 +635,7 @@ export const mockMeasurementModel = [
     upload_failed: false,
     scheduled_slot: null,
     scheduled_at: null,
+    server_timestamp: null,
     device_name: null,
     device_model: null,
     device_manufacturer: null,
@@ -685,6 +686,7 @@ export const mockMeasurementModel = [
     upload_failed: false,
     scheduled_slot: null,
     scheduled_at: null,
+    server_timestamp: null,
     device_name: null,
     device_model: null,
     device_manufacturer: null,
@@ -735,6 +737,7 @@ export const mockMeasurementModel = [
     upload_failed: false,
     scheduled_slot: null,
     scheduled_at: null,
+    server_timestamp: null,
     device_name: null,
     device_model: null,
     device_manufacturer: null,

src/measurement/measurement.dto.ts

@@ -749,6 +749,13 @@ export class MeasurementDto {
   })
   scheduled_at?: Date;
 
+  @ApiProperty({
+    required: false,
+    description:
+      "M-Lab's own clock as reported by ndt7, independent of the device clock. Null when the client could not read it",
+  })
+  server_timestamp?: Date;
+
   @ApiProperty({ required: false, description: 'Device name' })
   device_name?: string;
 

src/measurement/measurement.service.spec.ts

@@ -610,6 +610,50 @@ describe('MeasurementService', () => {
       });
     });
 
+    it('should persist the server timestamp reported by ndt7', async () => {
+      jest
+        .spyOn(prisma.dailycheckapp_school, 'findFirst')
+        .mockResolvedValue(mockSchoolModel[0]);
+      jest
+        .spyOn(prisma.giga_id_school_mapping_fix, 'findFirst')
+        .mockResolvedValue(null);
+      const createSpy = jest
+        .spyOn(prisma.measurements, 'create')
+        .mockResolvedValue(mockMeasurementModel[0]);
+
+      const serverTimestamp = new Date('2026-08-24T10:30:00.000Z');
+      await service.createMeasurement({
+        ...mockAddMeasurementDto[0],
+        server_timestamp: serverTimestamp,
+      });
+
+      expect(createSpy).toHaveBeenCalledWith({
+        data: expect.objectContaining({
+          server_timestamp: serverTimestamp,
+        }),
+      });
+    });
+
+    it('should store a null server timestamp when the app omits it', async () => {
+      jest
+        .spyOn(prisma.dailycheckapp_school, 'findFirst')
+        .mockResolvedValue(mockSchoolModel[0]);
+      jest
+        .spyOn(prisma.giga_id_school_mapping_fix, 'findFirst')
+        .mockResolvedValue(null);
+      const createSpy = jest
+        .spyOn(prisma.measurements, 'create')
+        .mockResolvedValue(mockMeasurementModel[0]);
+
+      await service.createMeasurement(mockAddMeasurementDto[0]);
+
+      expect(createSpy).toHaveBeenCalledWith({
+        data: expect.objectContaining({
+          server_timestamp: null,
+        }),
+      });
+    });
+
     it('should persist cloudflare protocol and derived quality metrics', async () => {
       jest
         .spyOn(prisma.dailycheckapp_school, 'findFirst')

src/measurement/measurement.service.ts

@@ -501,6 +501,7 @@ export class MeasurementService {
       upload_failed: measurement.upload_failed,
       scheduled_slot: measurement.scheduled_slot,
       scheduled_at: measurement.scheduled_at,
+      server_timestamp: measurement.server_timestamp,
       device_name: measurement.device_name,
       device_model: measurement.device_model,
       device_manufacturer: measurement.device_manufacturer,
@@ -659,6 +660,7 @@ export class MeasurementService {
       upload_failed: measurement.upload_failed ?? false,
       scheduled_slot: measurement.scheduled_slot ?? null,
       scheduled_at: measurement.scheduled_at ?? null,
+      server_timestamp: measurement.server_timestamp ?? null,
       device_name: measurement.device_name ?? null,
       device_model: measurement.device_model ?? null,
       device_manufacturer: measurement.device_manufacturer ?? null,

src/prisma/migrations/20260824130000_add_server_timestamp_to_measurements/migration.sql

@@ -0,0 +1,8 @@
+-- AlterTable
+-- server_timestamp: wall-clock time reported by M-Lab, captured by the ndt7
+-- client from the Date header of the locate service response. The existing
+-- `timestamp` column comes from the client machine's own clock, which on these
+-- devices is often wrong; this is a second, independent reference point rather
+-- than a replacement. Null for clients that do not send it, which is every
+-- release before app v2.0.4.
+ALTER TABLE "measurements" ADD COLUMN     "server_timestamp" TIMESTAMPTZ(6);

src/prisma/schema.prisma

@@ -317,6 +317,7 @@ model measurements {
   upload_failed               Boolean?  @default(false) // true = realtime upload failed, record arrived via offline sync
   scheduled_slot              String?   @db.VarChar(16) // 'A' | 'B' | 'C' | 'startup'; null for manual runs
   scheduled_at                DateTime? @db.Timestamptz(6) // originally planned run time of the scheduled test
+  server_timestamp            DateTime? @db.Timestamptz(6) // M-Lab's own clock, reported by ndt7; null when the client could not read it
   device_name                 String?
   device_model                String?
   device_manufacturer         String?