DashboardScenes: Fix issue where timezone was not considered in relative time override (#99316)

* Fix issue where timezone was not considered in relative time override

* fix

public/app/features/dashboard-scene/scene/PanelTimeRange.test.tsx

@@ -97,6 +97,20 @@ describe('PanelTimeRange', () => {
     expect(panelTime.state.from).toBe('now-12h');
     expect(panelTime.state.to).toBe('now-2h');
   });
+
+  it('should properly apply timeZone', () => {
+    const panelTime = new PanelTimeRange({ timeFrom: '2h' });
+
+    const panel = new SceneCanvasText({ text: 'Hello', $timeRange: panelTime });
+    const scene = new SceneFlexLayout({
+      $timeRange: new SceneTimeRange({ from: 'now-6h', to: 'now', timeZone: 'utc' }),
+      children: [new SceneFlexItem({ body: panel })],
+    });
+    activateFullSceneTree(scene);
+
+    expect(panelTime.state.value.from.format('Z')).toBe('+00:00'); // UTC
+    expect(panelTime.state.value.to.format('Z')).toBe('+00:00'); // UTC
+  });
 });
 
 function buildAndActivateSceneFor(panelTime: PanelTimeRange) {

public/app/features/dashboard-scene/scene/PanelTimeRange.tsx

@@ -81,10 +81,11 @@ export class PanelTimeRange extends SceneTimeRangeTransformerBase<PanelTimeRange
 
       // Only evaluate if the timeFrom if parent time is relative
       if (rangeUtil.isRelativeTimeRange(parentTimeRange.raw)) {
+        const timeZone = this.getTimeZone();
         newTimeData.timeInfo = timeFromInfo.display;
         newTimeData.timeRange = {
-          from: dateMath.parse(timeFromInfo.from)!,
-          to: dateMath.parse(timeFromInfo.to)!,
+          from: dateMath.parse(timeFromInfo.from, undefined, timeZone)!,
+          to: dateMath.parse(timeFromInfo.to, undefined, timeZone)!,
           raw: { from: timeFromInfo.from, to: timeFromInfo.to },
         };
       }