Improve timezone offset handling for latest values and alarm widgets. Improve ti…

…mezone selector - add local browser time info on empty value.

@@ -130,6 +130,7 @@ export class AlarmDataSubscription {
         this.alarmDataCommand.query.pageLink.timeWindow = this.subsTw.realtimeWindowMs;
       }
 
+      this.subscriber.setTsOffset(this.subsTw.tsOffset);
       this.subscriber.subscriptionCommands.push(this.alarmDataCommand);
 
       this.subscriber.alarmData$.subscribe((alarmDataUpdate) => {
@@ -143,8 +144,11 @@ export class AlarmDataSubscription {
       this.subscriber.subscribe();
 
     } else if (this.datasourceType === DatasourceType.function) {
+      const alarm = deepClone(simulatedAlarm);
+      alarm.createdTime += this.subsTw.tsOffset;
+      alarm.startTs += this.subsTw.tsOffset;
       const pageData: PageData<AlarmData> = {
-        data: [{...simulatedAlarm, entityId: '1', latest: {}}],
+        data: [{...alarm, entityId: '1', latest: {}}],
         hasNext: false,
         totalElements: 1,
         totalPages: 1

@@ -15,7 +15,7 @@
 ///
 
 import { DataSet, DataSetHolder, DatasourceType, widgetType } from '@shared/models/widget.models';
-import { AggregationType, SubscriptionTimewindow } from '@shared/models/time/time.models';
+import { AggregationType, getCurrentTime, SubscriptionTimewindow } from '@shared/models/time/time.models';
 import {
   EntityData,
   EntityDataPageLink,
@@ -74,6 +74,7 @@ export interface EntityDataSubscriptionOptions {
   keyFilters?: Array<KeyFilter>;
   additionalKeyFilters?: Array<KeyFilter>;
   subscriptionTimewindow?: SubscriptionTimewindow;
+  latestTsOffset?: number;
 }
 
 export class EntityDataSubscription {
@@ -95,6 +96,7 @@ export class EntityDataSubscription {
   private entityDataResolveSubject: Subject<EntityDataLoadResult>;
   private pageData: PageData<EntityData>;
   private subsTw: SubscriptionTimewindow;
+  private latestTsOffset: number;
   private dataAggregators: Array<DataAggregator>;
   private dataKeys: {[key: string]: Array<SubscriptionDataKey> | SubscriptionDataKey} = {};
   private datasourceData: {[index: number]: {[key: string]: DataSetHolder}};
@@ -177,6 +179,7 @@ export class EntityDataSubscription {
       this.started = true;
       this.dataResolved = true;
       this.subsTw = this.entityDataSubscriptionOptions.subscriptionTimewindow;
+      this.latestTsOffset = this.entityDataSubscriptionOptions.latestTsOffset;
       this.history = this.entityDataSubscriptionOptions.subscriptionTimewindow &&
         isObject(this.entityDataSubscriptionOptions.subscriptionTimewindow.fixedWindow);
       this.realtime = this.entityDataSubscriptionOptions.subscriptionTimewindow &&
@@ -237,7 +240,12 @@ export class EntityDataSubscription {
       };
 
       if (this.entityDataSubscriptionOptions.isPaginatedDataSubscription) {
-        this.prepareSubscriptionCommands();
+        this.prepareSubscriptionCommands(this.dataCommand);
+        if (this.entityDataSubscriptionOptions.type === widgetType.timeseries) {
+          this.subscriber.setTsOffset(this.subsTw.tsOffset);
+        } else {
+          this.subscriber.setTsOffset(this.latestTsOffset);
+        }
       }
 
       this.subscriber.subscriptionCommands.push(this.dataCommand);
@@ -276,9 +284,15 @@ export class EntityDataSubscription {
           this.subscriber.subscriptionCommands = [this.dataCommand];
         }
       });
-
       this.subscriber.subscribe();
     } else if (this.datasourceType === DatasourceType.function) {
+      let tsOffset = 0;
+      if (this.entityDataSubscriptionOptions.type === widgetType.latest) {
+        tsOffset = this.entityDataSubscriptionOptions.latestTsOffset;
+      } else if (this.entityDataSubscriptionOptions.subscriptionTimewindow) {
+        tsOffset = this.entityDataSubscriptionOptions.subscriptionTimewindow.tsOffset;
+      }
+
       const entityData: EntityData = {
         entityId: {
           id: NULL_UUID,
@@ -289,7 +303,7 @@ export class EntityDataSubscription {
       };
       const name = DatasourceType.function;
       entityData.latest[EntityKeyType.ENTITY_FIELD] = {
-        name: {ts: Date.now(), value: name}
+        name: {ts: Date.now() + tsOffset, value: name}
       };
       const pageData: PageData<EntityData> = {
         data: [entityData],
@@ -299,7 +313,9 @@ export class EntityDataSubscription {
       };
       this.onPageData(pageData);
     } else if (this.datasourceType === DatasourceType.entityCount) {
+      this.latestTsOffset = this.entityDataSubscriptionOptions.latestTsOffset;
       this.subscriber = new TelemetrySubscriber(this.telemetryService);
+      this.subscriber.setTsOffset(this.latestTsOffset);
       this.countCommand = new EntityCountCmd();
       let keyFilters = this.entityDataSubscriptionOptions.keyFilters;
       if (this.entityDataSubscriptionOptions.additionalKeyFilters) {
@@ -332,13 +348,13 @@ export class EntityDataSubscription {
               latest: {
                 [EntityKeyType.ENTITY_FIELD]: {
                   name: {
-                    ts: Date.now(),
+                    ts: Date.now() + this.latestTsOffset,
                     value: DatasourceType.entityCount
                   }
                 },
                 [EntityKeyType.COUNT]: {
                   [countKey.name]: {
-                    ts: Date.now(),
+                    ts: Date.now() + this.latestTsOffset,
                     value: entityCountUpdate.count + ''
                   }
                 }
@@ -359,7 +375,7 @@ export class EntityDataSubscription {
               latest: {
                 [EntityKeyType.COUNT]: {
                   [countKey.name]: {
-                    ts: Date.now(),
+                    ts: Date.now() + this.latestTsOffset,
                     value: entityCountUpdate.count + ''
                   }
                 }
@@ -384,6 +400,7 @@ export class EntityDataSubscription {
       return;
     }
     this.subsTw = this.entityDataSubscriptionOptions.subscriptionTimewindow;
+    this.latestTsOffset = this.entityDataSubscriptionOptions.latestTsOffset;
     this.history = this.entityDataSubscriptionOptions.subscriptionTimewindow &&
       isObject(this.entityDataSubscriptionOptions.subscriptionTimewindow.fixedWindow);
     this.realtime = this.entityDataSubscriptionOptions.subscriptionTimewindow &&
@@ -394,22 +411,38 @@ export class EntityDataSubscription {
     if (this.datasourceType === DatasourceType.entity) {
       this.subsCommand = new EntityDataCmd();
       this.subsCommand.cmdId = this.dataCommand.cmdId;
-      this.prepareSubscriptionCommands();
-      if (!this.subsCommand.isEmpty()) {
+      this.prepareSubscriptionCommands(this.subsCommand);
+      let latestTsOffsetChanged = false;
+      if (this.entityDataSubscriptionOptions.type === widgetType.timeseries) {
+        this.subscriber.setTsOffset(this.subsTw.tsOffset);
+      } else {
+        latestTsOffsetChanged = this.subscriber.setTsOffset(this.latestTsOffset);
+      }
+      if (latestTsOffsetChanged) {
+        if (this.listener.initialPageDataChanged) {
+          this.listener.initialPageDataChanged(this.pageData);
+        }
+      } else if (!this.subsCommand.isEmpty()) {
         this.subscriber.subscriptionCommands = [this.subsCommand];
         this.subscriber.update();
       }
+    } else if (this.datasourceType === DatasourceType.entityCount) {
+      if (this.subscriber.setTsOffset(this.latestTsOffset)) {
+        if (this.listener.initialPageDataChanged) {
+          this.listener.initialPageDataChanged(this.pageData);
+        }
+      }
     } else if (this.datasourceType === DatasourceType.function) {
       this.startFunction();
     }
     this.started = true;
   }
 
-  private prepareSubscriptionCommands() {
+  private prepareSubscriptionCommands(cmd: EntityDataCmd) {
     if (this.entityDataSubscriptionOptions.type === widgetType.timeseries) {
       if (this.tsFields.length > 0) {
         if (this.history) {
-          this.subsCommand.historyCmd = {
+          cmd.historyCmd = {
             keys: this.tsFields.map(key => key.key),
             startTs: this.subsTw.fixedWindow.startTimeMs,
             endTs: this.subsTw.fixedWindow.endTimeMs,
@@ -419,7 +452,7 @@ export class EntityDataSubscription {
             fetchLatestPreviousPoint: this.subsTw.aggregation.stateData
           };
         } else {
-          this.subsCommand.tsCmd = {
+          cmd.tsCmd = {
             keys: this.tsFields.map(key => key.key),
             startTs: this.subsTw.startTs,
             timeWindow: this.subsTw.aggregation.timeWindow,
@@ -430,10 +463,9 @@ export class EntityDataSubscription {
           };
         }
       }
-      this.subscriber.setTsOffset(this.subsTw.tsOffset);
     } else if (this.entityDataSubscriptionOptions.type === widgetType.latest) {
       if (this.latestValues.length > 0) {
-        this.subsCommand.latestCmd = {
+        cmd.latestCmd = {
           keys: this.latestValues
         };
       }
@@ -783,7 +815,7 @@ export class EntityDataSubscription {
     } else {
       prevSeries = [0, 0];
     }
-    const time = Date.now();
+    const time = Date.now() + this.latestTsOffset;
     const value = dataKey.func(time, prevSeries[1]);
     const series: [number, any] = [time, value];
     this.datasourceData[0][dataKey.key].data = [series];
@@ -838,6 +870,10 @@ export class EntityDataSubscription {
               endTime = this.entityDataSubscriptionOptions.subscriptionTimewindow.fixedWindow.endTimeMs +
                 this.entityDataSubscriptionOptions.subscriptionTimewindow.tsOffset;
             }
+            if (this.entityDataSubscriptionOptions.subscriptionTimewindow.quickInterval) {
+              const currentTime = getCurrentTime().valueOf() + this.entityDataSubscriptionOptions.subscriptionTimewindow.tsOffset;
+              endTime = Math.min(currentTime, endTime);
+            }
           }
           generatedData.data[`${dataKey.name}_${dataKey.index}`] = this.generateSeries(dataKey, index, startTime, endTime);
         }

@@ -32,6 +32,7 @@ import { Observable, of } from 'rxjs';
 export interface EntityDataListener {
   subscriptionType: widgetType;
   subscriptionTimewindow?: SubscriptionTimewindow;
+  latestTsOffset?: number;
   configDatasource: Datasource;
   configDatasourceIndex: number;
   dataLoaded: (pageData: PageData<EntityData>,
@@ -92,6 +93,8 @@ export class EntityDataService {
     if (listener.subscription) {
       if (listener.subscriptionType === widgetType.timeseries) {
         listener.subscriptionOptions.subscriptionTimewindow = deepClone(listener.subscriptionTimewindow);
+      } else if (listener.subscriptionType === widgetType.latest) {
+        listener.subscriptionOptions.latestTsOffset = listener.latestTsOffset;
       }
       listener.subscription.start();
     }
@@ -118,6 +121,8 @@ export class EntityDataService {
     listener.subscription = new EntityDataSubscription(listener, this.telemetryService, this.utils);
     if (listener.subscriptionType === widgetType.timeseries) {
       listener.subscriptionOptions.subscriptionTimewindow = deepClone(listener.subscriptionTimewindow);
+    } else if (listener.subscriptionType === widgetType.latest) {
+      listener.subscriptionOptions.latestTsOffset = listener.latestTsOffset;
     }
     return listener.subscription.subscribe();
   }

@@ -39,8 +39,10 @@ import { HttpErrorResponse } from '@angular/common/http';
 import {
   calculateIntervalEndTime,
   calculateIntervalStartTime,
+  calculateTsOffset,
   createSubscriptionTimewindow,
-  createTimewindowForComparison, getCurrentTime,
+  createTimewindowForComparison,
+  getCurrentTime,
   SubscriptionTimewindow,
   Timewindow,
   toHistoryTimewindow,
@@ -79,8 +81,10 @@ export class WidgetSubscription implements IWidgetSubscription {
   timeWindow: WidgetTimewindow;
   originalTimewindow: Timewindow;
   timeWindowConfig: Timewindow;
+  timezone: string;
   subscriptionTimewindow: SubscriptionTimewindow;
   useDashboardTimewindow: boolean;
+  tsOffset = 0;
 
   hasDataPageLink: boolean;
   singleEntity: boolean;
@@ -213,6 +217,10 @@ export class WidgetSubscription implements IWidgetSubscription {
       this.timeWindow = {};
       this.useDashboardTimewindow = options.useDashboardTimewindow;
       this.stateData = options.stateData;
+      if (this.type === widgetType.latest) {
+        this.timezone = options.dashboardTimewindow.timezone;
+        this.updateTsOffset();
+      }
       if (this.useDashboardTimewindow) {
         this.timeWindowConfig = deepClone(options.dashboardTimewindow);
       } else {
@@ -578,11 +586,16 @@ export class WidgetSubscription implements IWidgetSubscription {
         if (!isEqual(this.timeWindowConfig, newDashboardTimewindow) && newDashboardTimewindow) {
           this.timeWindowConfig = deepClone(newDashboardTimewindow);
           this.update();
-          return true;
+        }
+      }
+    } else if (this.type === widgetType.latest) {
+      if (newDashboardTimewindow && this.timezone !== newDashboardTimewindow.timezone) {
+        this.timezone = newDashboardTimewindow.timezone;
+        if (this.updateTsOffset()) {
+          this.update();
         }
       }
     }
-    return false;
   }
 
   updateDataVisibility(index: number): void {
@@ -815,6 +828,7 @@ export class WidgetSubscription implements IWidgetSubscription {
         configDatasource: datasource,
         configDatasourceIndex: datasourceIndex,
         subscriptionTimewindow: this.subscriptionTimewindow,
+        latestTsOffset: this.tsOffset,
         dataLoaded: (pageData, data1, datasourceIndex1, pageLink1) => {
           this.dataLoaded(pageData, data1, datasourceIndex1, pageLink1, true);
         },
@@ -882,25 +896,28 @@ export class WidgetSubscription implements IWidgetSubscription {
   }
 
   private dataSubscribe() {
+    this.updateDataTimewindow();
     if (!this.hasDataPageLink) {
-      if (this.type === widgetType.timeseries && this.timeWindowConfig) {
-        this.updateDataTimewindow();
-        if (this.subscriptionTimewindow.fixedWindow) {
+      if (this.type === widgetType.timeseries && this.timeWindowConfig && this.subscriptionTimewindow.fixedWindow) {
           this.onDataUpdated();
-        }
       }
       const forceUpdate = !this.datasources.length;
+      const notifyDataLoaded = !this.entityDataListeners.filter((listener) => listener.subscription ? true : false).length;
       this.entityDataListeners.forEach((listener) => {
         if (this.comparisonEnabled && listener.configDatasource.isAdditional) {
           listener.subscriptionTimewindow = this.timewindowForComparison;
         } else {
           listener.subscriptionTimewindow = this.subscriptionTimewindow;
+          listener.latestTsOffset = this.tsOffset;
         }
         this.ctx.entityDataService.startSubscription(listener);
       });
       if (forceUpdate) {
         this.onDataUpdated();
       }
+      if (notifyDataLoaded) {
+        this.notifyDataLoaded();
+      }
     }
   }
 
@@ -1102,6 +1119,15 @@ export class WidgetSubscription implements IWidgetSubscription {
     }
   }
 
+  private updateTsOffset(): boolean {
+    const newOffset = calculateTsOffset(this.timezone);
+    if (this.tsOffset !== newOffset) {
+      this.tsOffset = newOffset;
+      return true;
+    }
+    return false;
+  }
+
   private updateRealtimeSubscription(subscriptionTimewindow?: SubscriptionTimewindow): SubscriptionTimewindow {
     if (subscriptionTimewindow) {
       this.subscriptionTimewindow = subscriptionTimewindow;

@@ -133,7 +133,7 @@
             <mat-checkbox [ngModelOptions]="{standalone: true}" [(ngModel)]="timewindow.hideAggInterval"
                           (ngModelChange)="onHideAggIntervalChanged()"></mat-checkbox>
           </section>
-          <section fxLayout="column" [fxShow]="isEdit || !timewindow.hideAggInterval">
+          <section fxLayout="column" fxFlex [fxShow]="isEdit || !timewindow.hideAggInterval">
             <div class="limit-slider-container"
                  fxLayout="row" fxLayoutAlign="start center">
               <span translate>aggregation.limit</span>
@@ -184,7 +184,8 @@
                         (ngModelChange)="onHideTimezoneChanged()"></mat-checkbox>
         </section>
         <tb-timezone-select fxFlex [fxShow]="isEdit || !timewindow.hideTimezone"
-          formControlName="timezone">
+                        localBrowserTimezonePlaceholderOnEmpty="true"
+                        formControlName="timezone">
         </tb-timezone-select>
       </div>
       <div fxLayout="row" class="tb-panel-actions" fxLayoutAlign="end center">

@@ -23,7 +23,8 @@ import { AppState } from '@app/core/core.state';
 import { TranslateService } from '@ngx-translate/core';
 import { coerceBooleanProperty } from '@angular/cdk/coercion';
 import { MatAutocompleteTrigger } from '@angular/material/autocomplete';
-import { getTimezoneInfo, getTimezones, TimezoneInfo } from '@shared/models/time/time.models';
+import { getDefaultTimezoneInfo, getTimezoneInfo, getTimezones, TimezoneInfo } from '@shared/models/time/time.models';
+import { deepClone } from '@core/utils';
 
 @Component({
   selector: 'tb-timezone-select',
@@ -68,6 +69,15 @@ export class TimezoneSelectComponent implements ControlValueAccessor, OnInit, Af
     this.userTimezoneByDefaultValue = coerceBooleanProperty(value);
   }
 
+  private localBrowserTimezonePlaceholderOnEmptyValue: boolean;
+  get localBrowserTimezonePlaceholderOnEmpty(): boolean {
+    return this.localBrowserTimezonePlaceholderOnEmptyValue;
+  }
+  @Input()
+  set localBrowserTimezonePlaceholderOnEmpty(value: boolean) {
+    this.localBrowserTimezonePlaceholderOnEmptyValue = coerceBooleanProperty(value);
+  }
+
   @Input()
   disabled: boolean;
 
@@ -81,6 +91,10 @@ export class TimezoneSelectComponent implements ControlValueAccessor, OnInit, Af
 
   private dirty = false;
 
+  private localBrowserTimezoneInfoPlaceholder: TimezoneInfo;
+
+  private timezones: Array<TimezoneInfo>;
+
   private propagateChange = (v: any) => { };
 
   constructor(private store: Store<AppState>,
@@ -146,7 +160,11 @@ export class TimezoneSelectComponent implements ControlValueAccessor, OnInit, Af
       }
     } else {
       this.modelValue = null;
-      this.selectTimezoneFormGroup.get('timezone').patchValue('', {emitEvent: false});
+      if (this.localBrowserTimezonePlaceholderOnEmptyValue) {
+        this.selectTimezoneFormGroup.get('timezone').patchValue(this.getLocalBrowserTimezoneInfoPlaceholder(), {emitEvent: false});
+      } else {
+        this.selectTimezoneFormGroup.get('timezone').patchValue('', {emitEvent: false});
+      }
     }
     this.dirty = true;
   }
@@ -162,11 +180,17 @@ export class TimezoneSelectComponent implements ControlValueAccessor, OnInit, Af
     if (this.ignoreClosePanel) {
       this.ignoreClosePanel = false;
     } else {
-      if (!this.modelValue && (this.defaultTimezoneId || this.userTimezoneByDefaultValue)) {
-        const defaultTimezoneInfo = getTimezoneInfo(this.defaultTimezoneId, this.defaultTimezoneId, this.userTimezoneByDefaultValue);
-        if (defaultTimezoneInfo !== null) {
+      if (!this.modelValue) {
+        if (this.defaultTimezoneId || this.userTimezoneByDefaultValue) {
+          const defaultTimezoneInfo = getTimezoneInfo(this.defaultTimezoneId, this.defaultTimezoneId, this.userTimezoneByDefaultValue);
+          if (defaultTimezoneInfo !== null) {
+            this.ngZone.run(() => {
+              this.selectTimezoneFormGroup.get('timezone').reset(defaultTimezoneInfo, {emitEvent: true});
+            });
+          }
+        } else if (this.localBrowserTimezonePlaceholderOnEmptyValue) {
           this.ngZone.run(() => {
-            this.selectTimezoneFormGroup.get('timezone').reset(defaultTimezoneInfo, {emitEvent: true});
+            this.selectTimezoneFormGroup.get('timezone').reset(this.getLocalBrowserTimezoneInfoPlaceholder(), {emitEvent: true});
           });
         }
       }
@@ -187,10 +211,10 @@ export class TimezoneSelectComponent implements ControlValueAccessor, OnInit, Af
   fetchTimezones(searchText?: string): Observable<Array<TimezoneInfo>> {
     this.searchText = searchText;
     if (searchText && searchText.length) {
-      return of(getTimezones().filter((timezoneInfo) =>
+      return of(this.loadTimezones().filter((timezoneInfo) =>
           timezoneInfo.name.toLowerCase().includes(searchText.toLowerCase())));
     }
-    return of(getTimezones());
+    return of(this.loadTimezones());
   }
 
   clear() {
@@ -200,4 +224,23 @@ export class TimezoneSelectComponent implements ControlValueAccessor, OnInit, Af
     }, 0);
   }
 
+  private loadTimezones(): Array<TimezoneInfo> {
+    if (!this.timezones) {
+      this.timezones = [];
+      if (this.localBrowserTimezonePlaceholderOnEmptyValue) {
+        this.timezones.push(this.getLocalBrowserTimezoneInfoPlaceholder());
+      }
+      this.timezones.push(...getTimezones());
+    }
+    return this.timezones;
+  }
+
+  private getLocalBrowserTimezoneInfoPlaceholder(): TimezoneInfo {
+    if (!this.localBrowserTimezoneInfoPlaceholder) {
+      this.localBrowserTimezoneInfoPlaceholder = deepClone(getDefaultTimezoneInfo());
+      this.localBrowserTimezoneInfoPlaceholder.id = null;
+      this.localBrowserTimezoneInfoPlaceholder.name = this.translate.instant('timezone.browser-time');
+    }
+    return this.localBrowserTimezoneInfoPlaceholder;
+  }
 }

@@ -30,6 +30,9 @@ import {
   TsValue
 } from '@shared/models/query/query.models';
 import { PageData } from '@shared/models/page/page-data';
+import { alarmFields } from '@shared/models/alarm.models';
+import { entityFields } from '@shared/models/entity.models';
+import { isUndefined } from '@core/utils';
 
 export enum DataKeyType {
   timeseries = 'timeseries',
@@ -446,7 +449,9 @@ export class EntityDataUpdate extends DataUpdate<EntityData> {
         for (const key of Object.keys(entityData.timeseries)) {
           const tsValues = entityData.timeseries[key];
           for (const tsValue of tsValues) {
-            tsValue.ts += tsOffset;
+            if (tsValue.ts) {
+              tsValue.ts += tsOffset;
+            }
           }
         }
       }
@@ -455,13 +460,17 @@ export class EntityDataUpdate extends DataUpdate<EntityData> {
           const keyTypeValues = entityData.latest[entityKeyType];
           for (const key of Object.keys(keyTypeValues)) {
             const tsValue = keyTypeValues[key];
-            tsValue.ts += tsOffset;
+            if (tsValue.ts) {
+              tsValue.ts += tsOffset;
+            }
+            if (key === entityFields.createdTime.keyName && tsValue.value) {
+              tsValue.value = (Number(tsValue.value) + tsOffset) + '';
+            }
           }
         }
       }
     }
   }
-
 }
 
 export class AlarmDataUpdate extends DataUpdate<AlarmData> {
@@ -473,6 +482,48 @@ export class AlarmDataUpdate extends DataUpdate<AlarmData> {
     this.allowedEntities = msg.allowedEntities;
     this.totalEntities = msg.totalEntities;
   }
+
+  public prepareData(tsOffset: number) {
+    if (this.data) {
+      this.processAlarmData(this.data.data, tsOffset);
+    }
+    if (this.update) {
+      this.processAlarmData(this.update, tsOffset);
+    }
+  }
+
+  private processAlarmData(data: Array<AlarmData>, tsOffset: number) {
+    for (const alarmData of data) {
+      alarmData.createdTime += tsOffset;
+      if (alarmData.ackTs) {
+        alarmData.ackTs += tsOffset;
+      }
+      if (alarmData.clearTs) {
+        alarmData.clearTs += tsOffset;
+      }
+      if (alarmData.endTs) {
+        alarmData.endTs += tsOffset;
+      }
+      if (alarmData.latest) {
+        for (const entityKeyType of Object.keys(alarmData.latest)) {
+          const keyTypeValues = alarmData.latest[entityKeyType];
+          for (const key of Object.keys(keyTypeValues)) {
+            const tsValue = keyTypeValues[key];
+            if (tsValue.ts) {
+              tsValue.ts += tsOffset;
+            }
+            if (key in [entityFields.createdTime.keyName,
+                        alarmFields.startTime.keyName,
+                        alarmFields.endTime.keyName,
+                        alarmFields.ackTime.keyName,
+                        alarmFields.clearTime.keyName] && tsValue.value) {
+              tsValue.value = (Number(tsValue.value) + tsOffset) + '';
+            }
+          }
+        }
+      }
+    }
+  }
 }
 
 export class EntityCountUpdate extends CmdUpdate {
@@ -500,7 +551,7 @@ export class TelemetrySubscriber {
 
   private zone: NgZone;
 
-  private tsOffset = 0;
+  private tsOffset = undefined;
 
   public subscriptionCommands: Array<WebsocketCmd>;
 
@@ -556,8 +607,14 @@ export class TelemetrySubscriber {
     this.reconnectSubject.complete();
   }
 
-  public setTsOffset(tsOffset: number) {
-    this.tsOffset = tsOffset;
+  public setTsOffset(tsOffset: number): boolean {
+    if (this.tsOffset !== tsOffset) {
+      const changed = !isUndefined(this.tsOffset);
+      this.tsOffset = tsOffset;
+      return changed;
+    } else {
+      return false;
+    }
   }
 
   public onData(message: SubscriptionUpdate) {
@@ -598,6 +655,9 @@ export class TelemetrySubscriber {
   }
 
   public onAlarmData(message: AlarmDataUpdate) {
+    if (this.tsOffset) {
+      message.prepareData(this.tsOffset);
+    }
     if (this.zone) {
       this.zone.run(
         () => {

@@ -318,6 +318,16 @@ export function toHistoryTimewindow(timewindow: Timewindow, startTimeMs: number,
   return historyTimewindow;
 }
 
+export function calculateTsOffset(timezone?: string): number {
+  if (timezone) {
+    const tz = getTimezone(timezone);
+    const localOffset = moment().utcOffset();
+    return (tz.utcOffset() - localOffset) * 60 * 1000;
+  } else {
+    return 0;
+  }
+}
+
 export function createSubscriptionTimewindow(timewindow: Timewindow, stDiff: number, stateData: boolean,
                                              timeService: TimeService): SubscriptionTimewindow {
   const subscriptionTimewindow: SubscriptionTimewindow = {
@@ -329,13 +339,8 @@ export function createSubscriptionTimewindow(timewindow: Timewindow, stDiff: num
       type: AggregationType.AVG
     },
     timezone: timewindow.timezone,
-    tsOffset: 0
+    tsOffset: calculateTsOffset(timewindow.timezone)
   };
-  if (timewindow.timezone) {
-    const tz = getTimezone(timewindow.timezone);
-    const localOffset = moment().utcOffset();
-    subscriptionTimewindow.tsOffset = (tz.utcOffset() - localOffset) * 60 * 1000;
-  }
   let aggTimewindow = 0;
   if (stateData) {
     subscriptionTimewindow.aggregation.type = AggregationType.NONE;
@@ -407,6 +412,7 @@ export function createSubscriptionTimewindow(timewindow: Timewindow, stDiff: num
         endTimeMs: calculateIntervalEndTime(timewindow.history.quickInterval, currentDate)
       };
       aggTimewindow = subscriptionTimewindow.fixedWindow.endTimeMs - subscriptionTimewindow.fixedWindow.startTimeMs;
+      subscriptionTimewindow.quickInterval = timewindow.history.quickInterval;
     } else {
       subscriptionTimewindow.fixedWindow = {
         startTimeMs: timewindow.history.fixedTimewindow.startTimeMs - subscriptionTimewindow.tsOffset,
@@ -768,6 +774,11 @@ export function getTimezoneInfo(timezoneId: string, defaultTimezoneId?: string,
   return foundTimezone;
 }
 
+export function getDefaultTimezoneInfo(): TimezoneInfo {
+  const userTimezone = getDefaultTimezone();
+  return getTimezoneInfo(userTimezone);
+}
+
 export function getDefaultTimezone(): string {
   if (!defaultTimezone) {
     defaultTimezone = monentTz.tz.guess();

@@ -1988,7 +1988,8 @@
       "timezone": "Timezone",
       "select-timezone": "Select timezone",
       "no-timezones-matching": "No timezones matching '{{timezone}}' were found.",
-      "timezone-required": "Timezone is required."
+      "timezone-required": "Timezone is required.",
+      "browser-time": "Browser Time"
     },
     "queue": {
       "select_name": "Select queue name",