TimeSrv: Try to parse 8 and 15 digit numbers as timestamps if parsing as date fails (#21694)

* Try to parse 8 and 15 digit numbers as timestamps if parsing as date fails

Fixes #19738

* Add tests

public/app/features/dashboard/services/TimeSrv.test.ts

@@ -135,6 +135,38 @@ describe('timeSrv', () => {
       expect(time.to.valueOf()).toEqual(1410337665699);
     });
 
+    it('should handle epochs that look like formatted date without time', () => {
+      location = {
+        search: jest.fn(() => ({
+          from: '20149999',
+          to: '20159999',
+        })),
+      };
+
+      timeSrv = new TimeSrv(rootScope as any, jest.fn() as any, location as any, timer, new ContextSrvStub() as any);
+
+      timeSrv.init(_dashboard);
+      const time = timeSrv.timeRange();
+      expect(time.from.valueOf()).toEqual(20149999);
+      expect(time.to.valueOf()).toEqual(20159999);
+    });
+
+    it('should handle epochs that look like formatted date', () => {
+      location = {
+        search: jest.fn(() => ({
+          from: '201499991234567',
+          to: '201599991234567',
+        })),
+      };
+
+      timeSrv = new TimeSrv(rootScope as any, jest.fn() as any, location as any, timer, new ContextSrvStub() as any);
+
+      timeSrv.init(_dashboard);
+      const time = timeSrv.timeRange();
+      expect(time.from.valueOf()).toEqual(201499991234567);
+      expect(time.to.valueOf()).toEqual(201599991234567);
+    });
+
     it('should handle bad dates', () => {
       location = {
         search: jest.fn(() => ({

public/app/features/dashboard/services/TimeSrv.ts

@@ -102,10 +102,15 @@ export class TimeSrv {
       return value;
     }
     if (value.length === 8) {
-      return toUtc(value, 'YYYYMMDD');
-    }
-    if (value.length === 15) {
-      return toUtc(value, 'YYYYMMDDTHHmmss');
+      const utcValue = toUtc(value, 'YYYYMMDD');
+      if (utcValue.isValid()) {
+        return utcValue;
+      }
+    } else if (value.length === 15) {
+      const utcValue = toUtc(value, 'YYYYMMDDTHHmmss');
+      if (utcValue.isValid()) {
+        return utcValue;
+      }
     }
 
     if (!isNaN(value)) {