Add timezone support for timewindow

@@ -18,8 +18,8 @@ import { SubscriptionData, SubscriptionDataHolder } from '@app/shared/models/tel
 import {
   AggregationType,
   calculateIntervalEndTime,
-  calculateIntervalStartTime,
-  QuickTimeInterval
+  calculateIntervalStartTime, getCurrentTime,
+  QuickTimeInterval, SubscriptionTimewindow
 } from '@shared/models/time/time.models';
 import { UtilsService } from '@core/services/utils.service';
 import { deepClone } from '@core/utils';
@@ -78,34 +78,29 @@ export class DataAggregator {
   private resetPending = false;
   private updatedData = false;
 
-  private noAggregation = this.aggregationType === AggregationType.NONE;
-  private aggregationTimeout = Math.max(this.interval, 1000);
+  private noAggregation = this.subsTw.aggregation.type === AggregationType.NONE;
+  private aggregationTimeout = Math.max(this.subsTw.aggregation.interval, 1000);
   private readonly aggFunction: AggFunction;
 
   private intervalTimeoutHandle: Timeout;
   private intervalScheduledTime: number;
 
+  private startTs = this.subsTw.startTs + this.subsTw.tsOffset;
   private endTs: number;
   private elapsed: number;
 
   constructor(private onDataCb: onAggregatedData,
               private tsKeyNames: string[],
-              private startTs: number,
-              private limit: number,
-              private aggregationType: AggregationType,
-              private timeWindow: number,
-              private interval: number,
-              private stateData: boolean,
+              private subsTw: SubscriptionTimewindow,
               private utils: UtilsService,
-              private ignoreDataUpdateOnIntervalTick: boolean,
-              private quickInterval: QuickTimeInterval) {
+              private ignoreDataUpdateOnIntervalTick: boolean) {
     this.tsKeyNames.forEach((key) => {
       this.dataBuffer[key] = [];
     });
-    if (this.stateData) {
+    if (this.subsTw.aggregation.stateData) {
       this.lastPrevKvPairData = {};
     }
-    switch (this.aggregationType) {
+    switch (this.subsTw.aggregation.type) {
       case AggregationType.MIN:
         this.aggFunction = min;
         break;
@@ -135,19 +130,21 @@ export class DataAggregator {
     return prevOnDataCb;
   }
 
-  public reset(startTs: number, timeWindow: number, interval: number) {
+  public reset(subsTw: SubscriptionTimewindow) {
     if (this.intervalTimeoutHandle) {
       clearTimeout(this.intervalTimeoutHandle);
       this.intervalTimeoutHandle = null;
     }
+    this.subsTw = subsTw;
     this.intervalScheduledTime = this.utils.currentPerfTime();
-    this.startTs = startTs;
-    this.timeWindow = timeWindow;
-    this.interval = interval;
-    const endTs = this.startTs + this.timeWindow;
-    this.endTs = calculateIntervalEndTime(this.quickInterval, endTs);
+    this.startTs = this.subsTw.startTs + this.subsTw.tsOffset;
+    if (this.subsTw.quickInterval) {
+      this.endTs = calculateIntervalEndTime(this.subsTw.quickInterval, null, this.subsTw.timezone) + this.subsTw.tsOffset;
+    } else {
+      this.endTs = this.startTs + this.subsTw.aggregation.timeWindow;
+    }
     this.elapsed = 0;
-    this.aggregationTimeout = Math.max(this.interval, 1000);
+    this.aggregationTimeout = Math.max(this.subsTw.aggregation.interval, 1000);
     this.resetPending = true;
     this.updatedData = false;
     this.intervalTimeoutHandle = setTimeout(this.onInterval.bind(this), this.aggregationTimeout);
@@ -168,8 +165,11 @@ export class DataAggregator {
       if (!this.dataReceived) {
         this.elapsed = 0;
         this.dataReceived = true;
-        const endTs = this.startTs + this.timeWindow;
-        this.endTs = calculateIntervalEndTime(this.quickInterval, endTs);
+        if (this.subsTw.quickInterval) {
+          this.endTs = calculateIntervalEndTime(this.subsTw.quickInterval, null, this.subsTw.timezone) + this.subsTw.tsOffset;
+        } else {
+          this.endTs = this.startTs + this.subsTw.aggregation.timeWindow;
+        }
       }
       if (this.resetPending) {
         this.resetPending = false;
@@ -203,15 +203,19 @@ export class DataAggregator {
       this.intervalTimeoutHandle = null;
     }
     if (!history) {
-      const delta = Math.floor(this.elapsed / this.interval);
+      const delta = Math.floor(this.elapsed / this.subsTw.aggregation.interval);
       if (delta || !this.data) {
-        const tickTs = delta * this.interval;
-        const startTS = this.startTs + tickTs;
-        this.startTs = calculateIntervalStartTime(this.quickInterval, startTS);
-        const endTs = this.endTs + tickTs;
-        this.endTs = calculateIntervalEndTime(this.quickInterval, endTs);
+        const tickTs = delta * this.subsTw.aggregation.interval;
+        if (this.subsTw.quickInterval) {
+          const currentDate = getCurrentTime(this.subsTw.timezone);
+          this.startTs = calculateIntervalStartTime(this.subsTw.quickInterval, currentDate) + this.subsTw.tsOffset;
+          this.endTs = calculateIntervalEndTime(this.subsTw.quickInterval, currentDate) + this.subsTw.tsOffset;
+        } else {
+          this.startTs += tickTs;
+          this.endTs += tickTs;
+        }
         this.data = this.updateData();
-        this.elapsed = this.elapsed - delta * this.interval;
+        this.elapsed = this.elapsed - delta * this.subsTw.aggregation.interval;
       }
     } else {
       this.data = this.updateData();
@@ -234,7 +238,7 @@ export class DataAggregator {
       let keyData = this.dataBuffer[key];
       aggKeyData.forEach((aggData, aggTimestamp) => {
         if (aggTimestamp <= this.startTs) {
-          if (this.stateData &&
+          if (this.subsTw.aggregation.stateData &&
             (!this.lastPrevKvPairData[key] || this.lastPrevKvPairData[key][0] < aggTimestamp)) {
             this.lastPrevKvPairData[key] = [aggTimestamp, aggData.aggValue];
           }
@@ -246,11 +250,11 @@ export class DataAggregator {
         }
       });
       keyData.sort((set1, set2) => set1[0] - set2[0]);
-      if (this.stateData) {
+      if (this.subsTw.aggregation.stateData) {
         this.updateStateBounds(keyData, deepClone(this.lastPrevKvPairData[key]));
       }
-      if (keyData.length > this.limit) {
-        keyData = keyData.slice(keyData.length - this.limit);
+      if (keyData.length > this.subsTw.aggregation.limit) {
+        keyData = keyData.slice(keyData.length - this.subsTw.aggregation.limit);
       }
       this.dataBuffer[key] = keyData;
     }
@@ -286,7 +290,7 @@ export class DataAggregator {
   }
 
   private processAggregatedData(data: SubscriptionData): AggregationMap {
-    const isCount = this.aggregationType === AggregationType.COUNT;
+    const isCount = this.subsTw.aggregation.type === AggregationType.COUNT;
     const aggregationMap: AggregationMap = {};
     for (const key of Object.keys(data)) {
       let aggKeyData = aggregationMap[key];
@@ -311,7 +315,7 @@ export class DataAggregator {
   }
 
   private updateAggregatedData(data: SubscriptionData) {
-    const isCount = this.aggregationType === AggregationType.COUNT;
+    const isCount = this.subsTw.aggregation.type === AggregationType.COUNT;
     for (const key of Object.keys(data)) {
       let aggKeyData = this.aggregationMap[key];
       if (!aggKeyData) {
@@ -323,7 +327,8 @@ export class DataAggregator {
         const timestamp = kvPair[0];
         const value = this.convertValue(kvPair[1]);
         const aggTimestamp = this.noAggregation ? timestamp : (this.startTs +
-          Math.floor((timestamp - this.startTs) / this.interval) * this.interval + this.interval / 2);
+          Math.floor((timestamp - this.startTs) / this.subsTw.aggregation.interval) *
+          this.subsTw.aggregation.interval + this.subsTw.aggregation.interval / 2);
         let aggData = aggKeyData.get(aggTimestamp);
         if (!aggData) {
           aggData = {

@@ -237,7 +237,7 @@ export class EntityDataSubscription {
       };
 
       if (this.entityDataSubscriptionOptions.isPaginatedDataSubscription) {
-        this.prepareSubscriptionCommands(this.dataCommand);
+        this.prepareSubscriptionCommands();
       }
 
       this.subscriber.subscriptionCommands.push(this.dataCommand);
@@ -256,8 +256,8 @@ export class EntityDataSubscription {
         if (this.started) {
           const targetCommand = this.entityDataSubscriptionOptions.isPaginatedDataSubscription ? this.dataCommand : this.subsCommand;
           if (this.entityDataSubscriptionOptions.type === widgetType.timeseries &&
-              !this.history && this.tsFields.length) {
-            const newSubsTw: SubscriptionTimewindow = this.listener.updateRealtimeSubscription();
+            !this.history && this.tsFields.length) {
+            const newSubsTw = this.listener.updateRealtimeSubscription();
             this.subsTw = newSubsTw;
             targetCommand.tsCmd.startTs = this.subsTw.startTs;
             targetCommand.tsCmd.timeWindow = this.subsTw.aggregation.timeWindow;
@@ -266,9 +266,10 @@ export class EntityDataSubscription {
             targetCommand.tsCmd.agg = this.subsTw.aggregation.type;
             targetCommand.tsCmd.fetchLatestPreviousPoint = this.subsTw.aggregation.stateData;
             this.dataAggregators.forEach((dataAggregator) => {
-              dataAggregator.reset(newSubsTw.startTs,  newSubsTw.aggregation.timeWindow, newSubsTw.aggregation.interval);
+              dataAggregator.reset(newSubsTw);
             });
           }
+          this.subscriber.setTsOffset(this.subsTw.tsOffset);
           targetCommand.query = this.dataCommand.query;
           this.subscriber.subscriptionCommands = [targetCommand];
         } else {
@@ -393,7 +394,7 @@ export class EntityDataSubscription {
     if (this.datasourceType === DatasourceType.entity) {
       this.subsCommand = new EntityDataCmd();
       this.subsCommand.cmdId = this.dataCommand.cmdId;
-      this.prepareSubscriptionCommands(this.subsCommand);
+      this.prepareSubscriptionCommands();
       if (!this.subsCommand.isEmpty()) {
         this.subscriber.subscriptionCommands = [this.subsCommand];
         this.subscriber.update();
@@ -404,11 +405,11 @@ export class EntityDataSubscription {
     this.started = true;
   }
 
-  private prepareSubscriptionCommands(cmd: EntityDataCmd) {
+  private prepareSubscriptionCommands() {
     if (this.entityDataSubscriptionOptions.type === widgetType.timeseries) {
       if (this.tsFields.length > 0) {
         if (this.history) {
-          cmd.historyCmd = {
+          this.subsCommand.historyCmd = {
             keys: this.tsFields.map(key => key.key),
             startTs: this.subsTw.fixedWindow.startTimeMs,
             endTs: this.subsTw.fixedWindow.endTimeMs,
@@ -418,7 +419,7 @@ export class EntityDataSubscription {
             fetchLatestPreviousPoint: this.subsTw.aggregation.stateData
           };
         } else {
-          cmd.tsCmd = {
+          this.subsCommand.tsCmd = {
             keys: this.tsFields.map(key => key.key),
             startTs: this.subsTw.startTs,
             timeWindow: this.subsTw.aggregation.timeWindow,
@@ -429,9 +430,10 @@ export class EntityDataSubscription {
           };
         }
       }
+      this.subscriber.setTsOffset(this.subsTw.tsOffset);
     } else if (this.entityDataSubscriptionOptions.type === widgetType.latest) {
       if (this.latestValues.length > 0) {
-        cmd.latestCmd = {
+        this.subsCommand.latestCmd = {
           keys: this.latestValues
         };
       }
@@ -745,15 +747,9 @@ export class EntityDataSubscription {
         this.onData(data, dataKeyType, dataIndex, detectChanges, dataUpdatedCb);
       },
       tsKeyNames,
-      subsTw.startTs,
-      subsTw.aggregation.limit,
-      subsTw.aggregation.type,
-      subsTw.aggregation.timeWindow,
-      subsTw.aggregation.interval,
-      subsTw.aggregation.stateData,
+      subsTw,
       this.utils,
-      this.entityDataSubscriptionOptions.ignoreDataUpdateOnIntervalTick,
-      subsTw.quickInterval
+      this.entityDataSubscriptionOptions.ignoreDataUpdateOnIntervalTick
     );
   }
 
@@ -828,7 +824,8 @@ export class EntityDataSubscription {
                 startTime = dataKey.lastUpdateTime + this.frequency;
                 endTime = dataKey.lastUpdateTime + deltaElapsed;
               } else {
-                startTime = this.entityDataSubscriptionOptions.subscriptionTimewindow.startTs;
+                startTime = this.entityDataSubscriptionOptions.subscriptionTimewindow.startTs +
+                  this.entityDataSubscriptionOptions.subscriptionTimewindow.tsOffset;
                 endTime = startTime + this.entityDataSubscriptionOptions.subscriptionTimewindow.realtimeWindowMs + this.frequency;
                 if (this.entityDataSubscriptionOptions.subscriptionTimewindow.aggregation.type === AggregationType.NONE) {
                   const time = endTime - this.frequency * this.entityDataSubscriptionOptions.subscriptionTimewindow.aggregation.limit;
@@ -836,8 +833,10 @@ export class EntityDataSubscription {
                 }
               }
             } else {
-              startTime = this.entityDataSubscriptionOptions.subscriptionTimewindow.fixedWindow.startTimeMs;
-              endTime = this.entityDataSubscriptionOptions.subscriptionTimewindow.fixedWindow.endTimeMs;
+              startTime = this.entityDataSubscriptionOptions.subscriptionTimewindow.fixedWindow.startTimeMs +
+                this.entityDataSubscriptionOptions.subscriptionTimewindow.tsOffset;
+              endTime = this.entityDataSubscriptionOptions.subscriptionTimewindow.fixedWindow.endTimeMs +
+                this.entityDataSubscriptionOptions.subscriptionTimewindow.tsOffset;
             }
           }
           generatedData.data[`${dataKey.name}_${dataKey.index}`] = this.generateSeries(dataKey, index, startTime, endTime);

@@ -40,7 +40,7 @@ import {
   calculateIntervalEndTime,
   calculateIntervalStartTime,
   createSubscriptionTimewindow,
-  createTimewindowForComparison,
+  createTimewindowForComparison, getCurrentTime,
   SubscriptionTimewindow,
   Timewindow,
   toHistoryTimewindow,
@@ -839,9 +839,11 @@ export class WidgetSubscription implements IWidgetSubscription {
     if (this.alarmDataListener) {
       this.ctx.alarmDataService.stopSubscription(this.alarmDataListener);
     }
+
     if (this.timeWindowConfig) {
       this.updateRealtimeSubscription();
     }
+
     this.alarmDataListener = {
       subscriptionTimewindow: this.subscriptionTimewindow,
       alarmSource: this.alarmSource,
@@ -1082,14 +1084,21 @@ export class WidgetSubscription implements IWidgetSubscription {
 
   private updateTimewindow() {
     this.timeWindow.interval = this.subscriptionTimewindow.aggregation.interval || 1000;
+    this.timeWindow.timezone = this.subscriptionTimewindow.timezone;
     if (this.subscriptionTimewindow.realtimeWindowMs) {
-      this.timeWindow.maxTime = calculateIntervalEndTime(
-        this.subscriptionTimewindow.quickInterval, moment().valueOf() + this.timeWindow.stDiff);
-      this.timeWindow.minTime = calculateIntervalStartTime(
-        this.subscriptionTimewindow.quickInterval, this.timeWindow.maxTime - this.subscriptionTimewindow.realtimeWindowMs);
+      if (this.subscriptionTimewindow.quickInterval) {
+        const currentDate = getCurrentTime(this.subscriptionTimewindow.timezone);
+        this.timeWindow.maxTime = calculateIntervalEndTime(
+          this.subscriptionTimewindow.quickInterval, currentDate) + this.subscriptionTimewindow.tsOffset;
+        this.timeWindow.minTime = calculateIntervalStartTime(
+          this.subscriptionTimewindow.quickInterval, currentDate) + this.subscriptionTimewindow.tsOffset;
+      } else {
+        this.timeWindow.maxTime = moment().valueOf() + this.subscriptionTimewindow.tsOffset + this.timeWindow.stDiff;
+        this.timeWindow.minTime = this.timeWindow.maxTime - this.subscriptionTimewindow.realtimeWindowMs;
+      }
     } else if (this.subscriptionTimewindow.fixedWindow) {
-      this.timeWindow.maxTime = this.subscriptionTimewindow.fixedWindow.endTimeMs;
-      this.timeWindow.minTime = this.subscriptionTimewindow.fixedWindow.startTimeMs;
+      this.timeWindow.maxTime = this.subscriptionTimewindow.fixedWindow.endTimeMs + this.subscriptionTimewindow.tsOffset;
+      this.timeWindow.minTime = this.subscriptionTimewindow.fixedWindow.startTimeMs + this.subscriptionTimewindow.tsOffset;
     }
   }
 
@@ -1107,12 +1116,13 @@ export class WidgetSubscription implements IWidgetSubscription {
 
   private updateComparisonTimewindow() {
     this.comparisonTimeWindow.interval = this.timewindowForComparison.aggregation.interval || 1000;
+    this.comparisonTimeWindow.timezone = this.timewindowForComparison.timezone;
     if (this.timewindowForComparison.realtimeWindowMs) {
       this.comparisonTimeWindow.maxTime = moment(this.timeWindow.maxTime).subtract(1, this.timeForComparison).valueOf();
       this.comparisonTimeWindow.minTime = moment(this.timeWindow.minTime).subtract(1, this.timeForComparison).valueOf();
     } else if (this.timewindowForComparison.fixedWindow) {
-      this.comparisonTimeWindow.maxTime = this.timewindowForComparison.fixedWindow.endTimeMs;
-      this.comparisonTimeWindow.minTime = this.timewindowForComparison.fixedWindow.startTimeMs;
+      this.comparisonTimeWindow.maxTime = this.timewindowForComparison.fixedWindow.endTimeMs + this.timewindowForComparison.tsOffset;
+      this.comparisonTimeWindow.minTime = this.timewindowForComparison.fixedWindow.startTimeMs + this.timewindowForComparison.tsOffset;
     }
   }
 
@@ -1339,7 +1349,7 @@ export class WidgetSubscription implements IWidgetSubscription {
     this.onDataUpdated();
   }
 
-  private alarmsUpdated(_updated: Array<AlarmData>, alarms: PageData<AlarmData>) {
+  private alarmsUpdated(updated: Array<AlarmData>, alarms: PageData<AlarmData>) {
     this.alarmsLoaded(alarms, 0, 0);
   }
 

@@ -91,6 +91,7 @@
                          direction="left"
                          tooltipPosition="below"
                          aggregation="true"
+                         timezone="true"
                          [(ngModel)]="dashboardCtx.dashboardTimewindow">
           </tb-timewindow>
           <tb-filters-edit [fxShow]="!isEdit && displayFilters()"

@@ -95,6 +95,7 @@
               <tb-timewindow *ngIf="widget.hasTimewindow"
                              #timewindowComponent
                              aggregation="{{widget.hasAggregation}}"
+                             timezone="true"
                              [isEdit]="isEdit"
                              [(ngModel)]="widgetComponent.widget.config.timewindow"
                              (ngModelChange)="widgetComponent.onTimewindowChanged($event)">

@@ -55,7 +55,13 @@ import { EntityTypeTranslation } from '@shared/models/entity-type.models';
 import { DialogService } from '@core/services/dialog.service';
 import { AddEntityDialogComponent } from './add-entity-dialog.component';
 import { AddEntityDialogData, EntityAction } from '@home/models/entity/entity-component.models';
-import { HistoryWindowType, Timewindow } from '@shared/models/time/time.models';
+import {
+  calculateIntervalEndTime,
+  calculateIntervalStartTime,
+  getCurrentTime,
+  HistoryWindowType,
+  Timewindow
+} from '@shared/models/time/time.models';
 import { DomSanitizer, SafeHtml } from '@angular/platform-browser';
 import { TbAnchorComponent } from '@shared/components/tb-anchor.component';
 import { isDefined, isUndefined } from '@core/utils';
@@ -296,6 +302,10 @@ export class EntitiesTableComponent extends PageComponent implements AfterViewIn
         const currentTime = Date.now();
         timePageLink.startTime = currentTime - this.timewindow.history.timewindowMs;
         timePageLink.endTime = currentTime;
+      } else if (this.timewindow.history.historyType === HistoryWindowType.INTERVAL) {
+        const currentDate = getCurrentTime();
+        timePageLink.startTime = calculateIntervalStartTime(this.timewindow.history.quickInterval, currentDate);
+        timePageLink.endTime = calculateIntervalEndTime(this.timewindow.history.quickInterval, currentDate);
       } else {
         timePageLink.startTime = this.timewindow.history.fixedTimewindow.startTimeMs;
         timePageLink.endTime = this.timewindow.history.fixedTimewindow.endTimeMs;

@@ -94,11 +94,10 @@ export class AlarmScheduleComponent implements ControlValueAccessor, Validator,
       items: this.fb.array(Array.from({length: 7}, (value, i) => this.defaultItemsScheduler(i)), this.validateItems)
     });
     this.alarmScheduleForm.get('type').valueChanges.subscribe((type) => {
-      getDefaultTimezone().subscribe((defaultTimezone) => {
-        this.alarmScheduleForm.reset({type, items: this.defaultItems, timezone: defaultTimezone}, {emitEvent: false});
-        this.updateValidators(type, true);
-        this.alarmScheduleForm.updateValueAndValidity();
-      });
+      const defaultTimezone = getDefaultTimezone();
+      this.alarmScheduleForm.reset({type, items: this.defaultItems, timezone: defaultTimezone}, {emitEvent: false});
+      this.updateValidators(type, true);
+      this.alarmScheduleForm.updateValueAndValidity();
     });
     this.alarmScheduleForm.valueChanges.subscribe(() => {
       this.updateModel();

@@ -49,7 +49,7 @@
                         formControlName="quickInterval"
                         onlyCurrentInterval="true"
                         [fxShow]="timewindowForm.get('realtime.realtimeType').value === realtimeTypes.INTERVAL"
-                        [required]="timewindow.selectedTab === timewindowTypes.HISTORY &&
+                        [required]="timewindow.selectedTab === timewindowTypes.REALTIME &&
                                 timewindowForm.get('realtime.realtimeType').value === realtimeTypes.INTERVAL"
                         style="padding-top: 8px; min-width: 364px"></tb-quick-time-interval>
                     </section>
@@ -99,7 +99,7 @@
                         formControlName="quickInterval"
                         [fxShow]="timewindowForm.get('history.historyType').value === historyTypes.INTERVAL"
                         [required]="timewindow.selectedTab === timewindowTypes.HISTORY &&
-                                timewindowForm.get('history.historyType').value === historyTypes.INTERVAL"
+                              timewindowForm.get('history.historyType').value === historyTypes.INTERVAL"
                         style="padding-top: 8px; min-width: 364px"></tb-quick-time-interval>
                     </section>
                   </mat-radio-button>
@@ -177,6 +177,16 @@
           predefinedName="aggregation.group-interval">
         </tb-timeinterval>
       </div>
+      <div *ngIf="timezone" class="mat-content mat-padding" fxLayout="row">
+        <section fxLayout="column" [fxShow]="isEdit">
+          <label class="tb-small hide-label" translate>timewindow.hide</label>
+          <mat-checkbox [ngModelOptions]="{standalone: true}" [(ngModel)]="timewindow.hideTimezone"
+                        (ngModelChange)="onHideTimezoneChanged()"></mat-checkbox>
+        </section>
+        <tb-timezone-select fxFlex [fxShow]="isEdit || !timewindow.hideTimezone"
+          formControlName="timezone">
+        </tb-timezone-select>
+      </div>
       <div fxLayout="row" class="tb-panel-actions" fxLayoutAlign="end center">
         <button type="button"
                 mat-button

@@ -38,6 +38,7 @@ export interface TimewindowPanelData {
   historyOnly: boolean;
   timewindow: Timewindow;
   aggregation: boolean;
+  timezone: boolean;
   isEdit: boolean;
 }
 
@@ -52,6 +53,8 @@ export class TimewindowPanelComponent extends PageComponent implements OnInit {
 
   aggregation = false;
 
+  timezone = false;
+
   isEdit = false;
 
   timewindow: Timewindow;
@@ -82,6 +85,7 @@ export class TimewindowPanelComponent extends PageComponent implements OnInit {
     this.historyOnly = data.historyOnly;
     this.timewindow = data.timewindow;
     this.aggregation = data.aggregation;
+    this.timezone = data.timezone;
     this.isEdit = data.isEdit;
   }
 
@@ -89,6 +93,7 @@ export class TimewindowPanelComponent extends PageComponent implements OnInit {
     const hideInterval = this.timewindow.hideInterval || false;
     const hideAggregation = this.timewindow.hideAggregation || false;
     const hideAggInterval = this.timewindow.hideAggInterval || false;
+    const hideTimezone = this.timewindow.hideTimezone || false;
 
     this.timewindowForm = this.fb.group({
         realtime: this.fb.group(
@@ -154,7 +159,12 @@ export class TimewindowPanelComponent extends PageComponent implements OnInit {
               disabled: hideAggInterval
             }, [Validators.min(this.minDatapointsLimit()), Validators.max(this.maxDatapointsLimit())])
           }
-        )
+        ),
+        timezone: this.fb.control({
+          value: this.timewindow.timezone !== 'undefined'
+            ? this.timewindow.timezone : null,
+          disabled: hideTimezone
+        })
     });
   }
 
@@ -171,7 +181,7 @@ export class TimewindowPanelComponent extends PageComponent implements OnInit {
       timewindowMs: timewindowFormValue.history.timewindowMs,
       interval: timewindowFormValue.history.interval,
       fixedTimewindow: timewindowFormValue.history.fixedTimewindow,
-      quickInterval: timewindowFormValue.history.quickInterval
+      quickInterval: timewindowFormValue.history.quickInterval,
     };
     if (this.aggregation) {
       this.timewindow.aggregation = {
@@ -179,6 +189,9 @@ export class TimewindowPanelComponent extends PageComponent implements OnInit {
         limit: timewindowFormValue.aggregation.limit
       };
     }
+    if (this.timezone) {
+      this.timewindow.timezone = timewindowFormValue.timezone;
+    }
     this.result = this.timewindow;
     this.overlayRef.dispose();
   }
@@ -276,4 +289,13 @@ export class TimewindowPanelComponent extends PageComponent implements OnInit {
     this.timewindowForm.markAsDirty();
   }
 
+  onHideTimezoneChanged() {
+    if (this.timewindow.hideTimezone) {
+      this.timewindowForm.get('timezone').disable({emitEvent: false});
+    } else {
+      this.timewindowForm.get('timezone').enable({emitEvent: false});
+    }
+    this.timewindowForm.markAsDirty();
+  }
+
 }

@@ -91,6 +91,17 @@ export class TimewindowComponent implements OnInit, OnDestroy, ControlValueAcces
     return this.aggregationValue;
   }
 
+  timezoneValue = false;
+
+  @Input()
+  set timezone(val) {
+    this.timezoneValue = coerceBooleanProperty(val);
+  }
+
+  get timezone() {
+    return this.timezoneValue;
+  }
+
   isToolbarValue = false;
 
   @Input()
@@ -171,7 +182,7 @@ export class TimewindowComponent implements OnInit, OnDestroy, ControlValueAcces
     });
     if (isGtXs) {
       config.minWidth = '417px';
-      config.maxHeight = '440px';
+      config.maxHeight = '500px';
       const panelHeight = 375;
       const panelWidth = 417;
       const el = this.timewindowPanelOrigin.elementRef.nativeElement;
@@ -227,6 +238,7 @@ export class TimewindowComponent implements OnInit, OnDestroy, ControlValueAcces
         timewindow: deepClone(this.innerValue),
         historyOnly: this.historyOnly,
         aggregation: this.aggregation,
+        timezone: this.timezone,
         isEdit: this.isEdit
       }
     );

@@ -16,7 +16,7 @@
 
 import { AfterViewInit, Component, forwardRef, Input, NgZone, OnInit, ViewChild } from '@angular/core';
 import { ControlValueAccessor, FormBuilder, FormGroup, NG_VALUE_ACCESSOR } from '@angular/forms';
-import { Observable } from 'rxjs';
+import { Observable, of } from 'rxjs';
 import { map, mergeMap, share, tap } from 'rxjs/operators';
 import { Store } from '@ngrx/store';
 import { AppState } from '@app/core/core.state';
@@ -43,10 +43,6 @@ export class TimezoneSelectComponent implements ControlValueAccessor, OnInit, Af
 
   defaultTimezoneId: string = null;
 
-  timezones$ = getTimezones().pipe(
-    share()
-  );
-
   @Input()
   set defaultTimezone(timezone: string) {
     if (this.defaultTimezoneId !== timezone) {
@@ -138,23 +134,20 @@ export class TimezoneSelectComponent implements ControlValueAccessor, OnInit, Af
 
   writeValue(value: string | null): void {
     this.searchText = '';
-    getTimezoneInfo(value, this.defaultTimezoneId, this.userTimezoneByDefaultValue).subscribe(
-      (foundTimezone) => {
-        if (foundTimezone !== null) {
-          this.selectTimezoneFormGroup.get('timezone').patchValue(foundTimezone, {emitEvent: false});
-          if (foundTimezone.id !== value) {
-            setTimeout(() => {
-              this.updateView(foundTimezone.id);
-            }, 0);
-          } else {
-            this.modelValue = value;
-          }
-        } else {
-          this.modelValue = null;
-          this.selectTimezoneFormGroup.get('timezone').patchValue('', {emitEvent: false});
-        }
+    const foundTimezone = getTimezoneInfo(value, this.defaultTimezoneId, this.userTimezoneByDefaultValue);
+    if (foundTimezone !== null) {
+      this.selectTimezoneFormGroup.get('timezone').patchValue(foundTimezone, {emitEvent: false});
+      if (foundTimezone.id !== value) {
+        setTimeout(() => {
+          this.updateView(foundTimezone.id);
+        }, 0);
+      } else {
+        this.modelValue = value;
       }
-    );
+    } else {
+      this.modelValue = null;
+      this.selectTimezoneFormGroup.get('timezone').patchValue('', {emitEvent: false});
+    }
     this.dirty = true;
   }
 
@@ -170,14 +163,12 @@ export class TimezoneSelectComponent implements ControlValueAccessor, OnInit, Af
       this.ignoreClosePanel = false;
     } else {
       if (!this.modelValue && (this.defaultTimezoneId || this.userTimezoneByDefaultValue)) {
-        getTimezoneInfo(this.defaultTimezoneId, this.defaultTimezoneId, this.userTimezoneByDefaultValue).subscribe(
-          (defaultTimezoneInfo) => {
-            if (defaultTimezoneInfo !== null) {
-              this.ngZone.run(() => {
-                this.selectTimezoneFormGroup.get('timezone').reset(defaultTimezoneInfo, {emitEvent: true});
-              });
-            }
-       });
+        const defaultTimezoneInfo = getTimezoneInfo(this.defaultTimezoneId, this.defaultTimezoneId, this.userTimezoneByDefaultValue);
+        if (defaultTimezoneInfo !== null) {
+          this.ngZone.run(() => {
+            this.selectTimezoneFormGroup.get('timezone').reset(defaultTimezoneInfo, {emitEvent: true});
+          });
+        }
       }
     }
   }
@@ -196,12 +187,10 @@ export class TimezoneSelectComponent implements ControlValueAccessor, OnInit, Af
   fetchTimezones(searchText?: string): Observable<Array<TimezoneInfo>> {
     this.searchText = searchText;
     if (searchText && searchText.length) {
-      return getTimezones().pipe(
-        map((timezones) => timezones.filter((timezoneInfo) =>
-          timezoneInfo.name.toLowerCase().includes(searchText.toLowerCase())))
-      );
+      return of(getTimezones().filter((timezoneInfo) =>
+          timezoneInfo.name.toLowerCase().includes(searchText.toLowerCase())));
     }
-    return getTimezones();
+    return of(getTimezones());
   }
 
   clear() {

@@ -430,6 +430,38 @@ export class EntityDataUpdate extends DataUpdate<EntityData> {
   constructor(msg: EntityDataUpdateMsg) {
     super(msg);
   }
+
+  public prepareData(tsOffset: number) {
+    if (this.data) {
+      this.processEntityData(this.data.data, tsOffset);
+    }
+    if (this.update) {
+      this.processEntityData(this.update, tsOffset);
+    }
+  }
+
+  private processEntityData(data: Array<EntityData>, tsOffset: number) {
+    for (const entityData of data) {
+      if (entityData.timeseries) {
+        for (const key of Object.keys(entityData.timeseries)) {
+          const tsValues = entityData.timeseries[key];
+          for (const tsValue of tsValues) {
+            tsValue.ts += tsOffset;
+          }
+        }
+      }
+      if (entityData.latest) {
+        for (const entityKeyType of Object.keys(entityData.latest)) {
+          const keyTypeValues = entityData.latest[entityKeyType];
+          for (const key of Object.keys(keyTypeValues)) {
+            const tsValue = keyTypeValues[key];
+            tsValue.ts += tsOffset;
+          }
+        }
+      }
+    }
+  }
+
 }
 
 export class AlarmDataUpdate extends DataUpdate<AlarmData> {
@@ -468,6 +500,8 @@ export class TelemetrySubscriber {
 
   private zone: NgZone;
 
+  private tsOffset = 0;
+
   public subscriptionCommands: Array<WebsocketCmd>;
 
   public data$ = this.dataSubject.asObservable();
@@ -522,6 +556,10 @@ export class TelemetrySubscriber {
     this.reconnectSubject.complete();
   }
 
+  public setTsOffset(tsOffset: number) {
+    this.tsOffset = tsOffset;
+  }
+
   public onData(message: SubscriptionUpdate) {
     const cmdId = message.subscriptionId;
     let keys: string[];
@@ -545,6 +583,9 @@ export class TelemetrySubscriber {
   }
 
   public onEntityData(message: EntityDataUpdate) {
+    if (this.tsOffset) {
+      message.prepareData(this.tsOffset);
+    }
     if (this.zone) {
       this.zone.run(
         () => {

@@ -15,11 +15,9 @@
 ///
 
 import { TimeService } from '@core/services/time.service';
-import { deepClone, isDefined, isDefinedAndNotNull, isUndefined } from '@app/core/utils';
+import { deepClone, isDefined, isUndefined } from '@app/core/utils';
 import * as moment_ from 'moment';
-import { Observable } from 'rxjs/internal/Observable';
-import { from, of } from 'rxjs';
-import { map, mergeMap, tap } from 'rxjs/operators';
+import * as monentTz from 'moment-timezone';
 
 const moment = moment_;
 
@@ -97,10 +95,12 @@ export interface Timewindow {
   hideInterval?: boolean;
   hideAggregation?: boolean;
   hideAggInterval?: boolean;
+  hideTimezone?: boolean;
   selectedTab?: TimewindowType;
   realtime?: RealtimeWindow;
   history?: HistoryWindow;
   aggregation?: Aggregation;
+  timezone?: string;
 }
 
 export interface SubscriptionAggregation extends Aggregation {
@@ -112,6 +112,8 @@ export interface SubscriptionAggregation extends Aggregation {
 export interface SubscriptionTimewindow {
   startTs?: number;
   quickInterval?: QuickTimeInterval;
+  timezone?: string;
+  tsOffset?: number;
   realtimeWindowMs?: number;
   fixedWindow?: FixedWindow;
   aggregation?: SubscriptionAggregation;
@@ -121,6 +123,7 @@ export interface WidgetTimewindow {
   minTime?: number;
   maxTime?: number;
   interval?: number;
+  timezone?: string;
   stDiff?: number;
 }
 
@@ -178,6 +181,7 @@ export function defaultTimewindow(timeService: TimeService): Timewindow {
     hideInterval: false,
     hideAggregation: false,
     hideAggInterval: false,
+    hideTimezone: false,
     selectedTab: TimewindowType.REALTIME,
     realtime: {
       realtimeType: RealtimeWindowType.LAST_INTERVAL,
@@ -209,6 +213,7 @@ export function initModelFromDefaultTimewindow(value: Timewindow, timeService: T
     model.hideInterval = value.hideInterval;
     model.hideAggregation = value.hideAggregation;
     model.hideAggInterval = value.hideAggInterval;
+    model.hideTimezone = value.hideTimezone;
     if (isUndefined(value.selectedTab)) {
       if (value.realtime) {
         model.selectedTab = TimewindowType.REALTIME;
@@ -266,6 +271,7 @@ export function initModelFromDefaultTimewindow(value: Timewindow, timeService: T
       }
       model.aggregation.limit = value.aggregation.limit || Math.floor(timeService.getMaxDatapointsLimit() / 2);
     }
+    model.timezone = value.timezone;
   }
   return model;
 }
@@ -292,6 +298,7 @@ export function toHistoryTimewindow(timewindow: Timewindow, startTimeMs: number,
     hideInterval: timewindow.hideInterval || false,
     hideAggregation: timewindow.hideAggregation || false,
     hideAggInterval: timewindow.hideAggInterval || false,
+    hideTimezone: timewindow.hideTimezone || false,
     selectedTab: TimewindowType.HISTORY,
     history: {
       historyType: HistoryWindowType.FIXED,
@@ -304,7 +311,8 @@ export function toHistoryTimewindow(timewindow: Timewindow, startTimeMs: number,
     aggregation: {
       type: aggType,
       limit
-    }
+    },
+    timezone: timewindow.timezone
   };
   return historyTimewindow;
 }
@@ -318,8 +326,15 @@ export function createSubscriptionTimewindow(timewindow: Timewindow, stDiff: num
       interval: SECOND,
       limit: timeService.getMaxDatapointsLimit(),
       type: AggregationType.AVG
-    }
+    },
+    timezone: timewindow.timezone,
+    tsOffset: 0
   };
+  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;
@@ -345,20 +360,25 @@ export function createSubscriptionTimewindow(timewindow: Timewindow, stDiff: num
       }
     }
     if (realtimeType === RealtimeWindowType.INTERVAL) {
-      subscriptionTimewindow.realtimeWindowMs = getSubscriptionRealtimeWindowFromTimeInterval(timewindow.realtime.quickInterval);
+      const currentDate = getCurrentTime(timewindow.timezone);
+      subscriptionTimewindow.realtimeWindowMs =
+        getSubscriptionRealtimeWindowFromTimeInterval(timewindow.realtime.quickInterval, currentDate);
       subscriptionTimewindow.quickInterval = timewindow.realtime.quickInterval;
+      subscriptionTimewindow.startTs = calculateIntervalStartTime(timewindow.realtime.quickInterval, currentDate);
     } else {
       subscriptionTimewindow.realtimeWindowMs = timewindow.realtime.timewindowMs;
+      subscriptionTimewindow.startTs = Date.now() + stDiff - subscriptionTimewindow.realtimeWindowMs;
     }
     subscriptionTimewindow.aggregation.interval =
       timeService.boundIntervalToTimewindow(subscriptionTimewindow.realtimeWindowMs, timewindow.realtime.interval,
         subscriptionTimewindow.aggregation.type);
-    subscriptionTimewindow.startTs = Date.now() + stDiff - subscriptionTimewindow.realtimeWindowMs;
-    const startDiff = subscriptionTimewindow.startTs % subscriptionTimewindow.aggregation.interval;
     aggTimewindow = subscriptionTimewindow.realtimeWindowMs;
-    if (startDiff && realtimeType !== RealtimeWindowType.INTERVAL) {
-      subscriptionTimewindow.startTs -= startDiff;
-      aggTimewindow += subscriptionTimewindow.aggregation.interval;
+    if (realtimeType !== RealtimeWindowType.INTERVAL) {
+      const startDiff = subscriptionTimewindow.startTs % subscriptionTimewindow.aggregation.interval;
+      if (startDiff) {
+        subscriptionTimewindow.startTs -= startDiff;
+        aggTimewindow += subscriptionTimewindow.aggregation.interval;
+      }
     }
   } else {
     let historyType = timewindow.history.historyType;
@@ -372,23 +392,24 @@ export function createSubscriptionTimewindow(timewindow: Timewindow, stDiff: num
       }
     }
     if (historyType === HistoryWindowType.LAST_INTERVAL) {
-      const currentTime = Date.now();
+      const currentDate = getCurrentTime(timewindow.timezone);
+      const currentTime = currentDate.valueOf();
       subscriptionTimewindow.fixedWindow = {
         startTimeMs: currentTime - timewindow.history.timewindowMs,
         endTimeMs: currentTime
       };
       aggTimewindow = timewindow.history.timewindowMs;
     } else if (historyType === HistoryWindowType.INTERVAL) {
-      const currentDate = moment();
+      const currentDate = getCurrentTime(timewindow.timezone);
       subscriptionTimewindow.fixedWindow = {
-        startTimeMs: calculateIntervalStartTime(timewindow.history.quickInterval, null, currentDate),
-        endTimeMs: calculateIntervalEndTime(timewindow.history.quickInterval, null, currentDate)
+        startTimeMs: calculateIntervalStartTime(timewindow.history.quickInterval, currentDate),
+        endTimeMs: calculateIntervalEndTime(timewindow.history.quickInterval, currentDate)
       };
       aggTimewindow = subscriptionTimewindow.fixedWindow.endTimeMs - subscriptionTimewindow.fixedWindow.startTimeMs;
     } else {
       subscriptionTimewindow.fixedWindow = {
-        startTimeMs: timewindow.history.fixedTimewindow.startTimeMs,
-        endTimeMs: timewindow.history.fixedTimewindow.endTimeMs
+        startTimeMs: timewindow.history.fixedTimewindow.startTimeMs - subscriptionTimewindow.tsOffset,
+        endTimeMs: timewindow.history.fixedTimewindow.endTimeMs - subscriptionTimewindow.tsOffset
       };
       aggTimewindow = subscriptionTimewindow.fixedWindow.endTimeMs - subscriptionTimewindow.fixedWindow.startTimeMs;
     }
@@ -404,88 +425,85 @@ export function createSubscriptionTimewindow(timewindow: Timewindow, stDiff: num
   return subscriptionTimewindow;
 }
 
-function getSubscriptionRealtimeWindowFromTimeInterval(interval: QuickTimeInterval): number {
-  const currentDate = moment();
+function getSubscriptionRealtimeWindowFromTimeInterval(interval: QuickTimeInterval, currentDate: moment_.Moment): number {
   switch (interval) {
     case QuickTimeInterval.CURRENT_HOUR:
-      return currentDate.diff(currentDate.clone().startOf('hour'))
+      return HOUR;
     case QuickTimeInterval.CURRENT_DAY:
     case QuickTimeInterval.CURRENT_DAY_SO_FAR:
-      return currentDate.diff(currentDate.clone().startOf('day'));
+      return DAY;
     case QuickTimeInterval.CURRENT_WEEK:
     case QuickTimeInterval.CURRENT_WEEK_SO_FAR:
-      return currentDate.diff(currentDate.clone().startOf('week'));
+      return WEEK;
     case QuickTimeInterval.CURRENT_MONTH:
     case QuickTimeInterval.CURRENT_MONTH_SO_FAR:
-      return currentDate.diff(currentDate.clone().startOf('month'));
+      return currentDate.endOf('month').diff(currentDate.clone().startOf('month'));
     case QuickTimeInterval.CURRENT_YEAR:
     case QuickTimeInterval.CURRENT_YEAR_SO_FAR:
-      return currentDate.diff(currentDate.clone().startOf('year'));
+      return currentDate.endOf('year').diff(currentDate.clone().startOf('year'));
   }
 }
 
-export function calculateIntervalEndTime(interval: QuickTimeInterval, endTs = 0, nowDate?: moment_.Moment): number {
-  const currentDate = isDefinedAndNotNull(nowDate) ? nowDate.clone() : moment();
-  switch (interval) {
-    case QuickTimeInterval.YESTERDAY:
-      currentDate.subtract(1, 'days');
-      return currentDate.endOf('day').valueOf();
-    case QuickTimeInterval.DAY_BEFORE_YESTERDAY:
-      currentDate.subtract(2, 'days');
-      return currentDate.endOf('day').valueOf();
-    case QuickTimeInterval.THIS_DAY_LAST_WEEK:
-      currentDate.subtract(1, 'weeks');
-      return currentDate.endOf('day').valueOf();
-    case QuickTimeInterval.PREVIOUS_WEEK:
-      currentDate.subtract(1, 'weeks');
-      return currentDate.endOf('week').valueOf();
-    case QuickTimeInterval.PREVIOUS_MONTH:
-      currentDate.subtract(1, 'months');
-      return currentDate.endOf('month').valueOf();
-    case QuickTimeInterval.PREVIOUS_YEAR:
-      currentDate.subtract(1, 'years');
-      return currentDate.endOf('year').valueOf();
-    case QuickTimeInterval.CURRENT_HOUR:
-      return currentDate.endOf('hour').valueOf();
-    case QuickTimeInterval.CURRENT_DAY:
-      return currentDate.endOf('day').valueOf();
-    case QuickTimeInterval.CURRENT_WEEK:
-      return currentDate.endOf('week').valueOf();
-    case QuickTimeInterval.CURRENT_MONTH:
-      return currentDate.endOf('month').valueOf();
-    case QuickTimeInterval.CURRENT_YEAR:
-      return currentDate.endOf('year').valueOf();
-    case QuickTimeInterval.CURRENT_DAY_SO_FAR:
-    case QuickTimeInterval.CURRENT_WEEK_SO_FAR:
-    case QuickTimeInterval.CURRENT_MONTH_SO_FAR:
-    case QuickTimeInterval.CURRENT_YEAR_SO_FAR:
-      return currentDate.valueOf();
-    default:
-      return endTs;
+export function calculateIntervalEndTime(interval: QuickTimeInterval, currentDate: moment_.Moment = null, tz: string = ''): number {
+    currentDate = currentDate ? currentDate.clone() : getCurrentTime(tz);
+    switch (interval) {
+      case QuickTimeInterval.YESTERDAY:
+        currentDate.subtract(1, 'days');
+        return currentDate.endOf('day').valueOf();
+      case QuickTimeInterval.DAY_BEFORE_YESTERDAY:
+        currentDate.subtract(2, 'days');
+        return currentDate.endOf('day').valueOf();
+      case QuickTimeInterval.THIS_DAY_LAST_WEEK:
+        currentDate.subtract(1, 'weeks');
+        return currentDate.endOf('day').valueOf();
+      case QuickTimeInterval.PREVIOUS_WEEK:
+        currentDate.subtract(1, 'weeks');
+        return currentDate.endOf('week').valueOf();
+      case QuickTimeInterval.PREVIOUS_MONTH:
+        currentDate.subtract(1, 'months');
+        return currentDate.endOf('month').valueOf();
+      case QuickTimeInterval.PREVIOUS_YEAR:
+        currentDate.subtract(1, 'years');
+        return currentDate.endOf('year').valueOf();
+      case QuickTimeInterval.CURRENT_HOUR:
+        return currentDate.endOf('hour').valueOf();
+      case QuickTimeInterval.CURRENT_DAY:
+        return currentDate.endOf('day').valueOf();
+      case QuickTimeInterval.CURRENT_WEEK:
+        return currentDate.endOf('week').valueOf();
+      case QuickTimeInterval.CURRENT_MONTH:
+        return currentDate.endOf('month').valueOf();
+      case QuickTimeInterval.CURRENT_YEAR:
+        return currentDate.endOf('year').valueOf();
+      case QuickTimeInterval.CURRENT_DAY_SO_FAR:
+      case QuickTimeInterval.CURRENT_WEEK_SO_FAR:
+      case QuickTimeInterval.CURRENT_MONTH_SO_FAR:
+      case QuickTimeInterval.CURRENT_YEAR_SO_FAR:
+        return currentDate.valueOf();
   }
 }
 
-export function calculateIntervalStartTime(interval: QuickTimeInterval, startTS = 0, nowDate?: moment_.Moment): number {
-  const currentDate = isDefinedAndNotNull(nowDate) ? nowDate.clone() : moment();
+export function calculateIntervalStartTime(interval: QuickTimeInterval, currentDate: moment_.Moment = null, tz: string = ''): number {
+  currentDate = currentDate ? currentDate.clone() : getCurrentTime(tz);
   switch (interval) {
     case QuickTimeInterval.YESTERDAY:
       currentDate.subtract(1, 'days');
-      return  currentDate.startOf('day').valueOf();
+      return currentDate.startOf('day').valueOf();
     case QuickTimeInterval.DAY_BEFORE_YESTERDAY:
       currentDate.subtract(2, 'days');
       return currentDate.startOf('day').valueOf();
     case QuickTimeInterval.THIS_DAY_LAST_WEEK:
       currentDate.subtract(1, 'weeks');
-      return  currentDate.startOf('day').valueOf();
+      return currentDate.startOf('day').valueOf();
     case QuickTimeInterval.PREVIOUS_WEEK:
       currentDate.subtract(1, 'weeks');
-      return  currentDate.startOf('week').valueOf();
+      return currentDate.startOf('week').valueOf();
     case QuickTimeInterval.PREVIOUS_MONTH:
       currentDate.subtract(1, 'months');
-      return  currentDate.startOf('month').valueOf();
+      return currentDate.startOf('month').valueOf();
     case QuickTimeInterval.PREVIOUS_YEAR:
       currentDate.subtract(1, 'years');
-      return  currentDate.startOf('year').valueOf();
+      return currentDate.startOf('year').valueOf();
     case QuickTimeInterval.CURRENT_HOUR:
       return currentDate.startOf('hour').valueOf();
     case QuickTimeInterval.CURRENT_DAY:
@@ -500,8 +518,6 @@ export function calculateIntervalStartTime(interval: QuickTimeInterval, startTS
     case QuickTimeInterval.CURRENT_YEAR:
     case QuickTimeInterval.CURRENT_YEAR_SO_FAR:
       return currentDate.startOf('year').valueOf();
-    default:
-      return startTS;
   }
 }
 
@@ -560,6 +576,7 @@ export function cloneSelectedTimewindow(timewindow: Timewindow): Timewindow {
   cloned.hideInterval = timewindow.hideInterval || false;
   cloned.hideAggregation = timewindow.hideAggregation || false;
   cloned.hideAggInterval = timewindow.hideAggInterval || false;
+  cloned.hideTimezone = timewindow.hideTimezone || false;
   if (isDefined(timewindow.selectedTab)) {
     cloned.selectedTab = timewindow.selectedTab;
     if (timewindow.selectedTab === TimewindowType.REALTIME) {
@@ -569,6 +586,7 @@ export function cloneSelectedTimewindow(timewindow: Timewindow): Timewindow {
     }
   }
   cloned.aggregation = deepClone(timewindow.aggregation);
+  cloned.timezone = timewindow.timezone;
   return cloned;
 }
 
@@ -718,60 +736,50 @@ export interface TimezoneInfo {
 let timezones: TimezoneInfo[] = null;
 let defaultTimezone: string = null;
 
-export function getTimezones(): Observable<TimezoneInfo[]> {
-  if (timezones) {
-    return of(timezones);
-  } else {
-    return from(import('moment-timezone')).pipe(
-      map((monentTz) => {
-        return monentTz.tz.names().map((zoneName) => {
-          const tz = monentTz.tz(zoneName);
-          return {
-            id: zoneName,
-            name: zoneName.replace(/_/g, ' '),
-            offset: `UTC${tz.format('Z')}`,
-            nOffset: tz.utcOffset()
-          };
-        });
-      }),
-      tap((zones) => {
-        timezones = zones;
-      })
-    );
+export function getTimezones(): TimezoneInfo[] {
+  if (!timezones) {
+    timezones = monentTz.tz.names().map((zoneName) => {
+      const tz = monentTz.tz(zoneName);
+      return {
+        id: zoneName,
+        name: zoneName.replace(/_/g, ' '),
+        offset: `UTC${tz.format('Z')}`,
+        nOffset: tz.utcOffset()
+      };
+    });
+  }
+  return timezones;
+}
+
+export function getTimezoneInfo(timezoneId: string, defaultTimezoneId?: string, userTimezoneByDefault?: boolean): TimezoneInfo {
+  const timezoneList = getTimezones();
+  let foundTimezone = timezoneId ? timezoneList.find(timezoneInfo => timezoneInfo.id === timezoneId) : null;
+  if (!foundTimezone) {
+    if (userTimezoneByDefault) {
+      const userTimezone = getDefaultTimezone();
+      foundTimezone = timezoneList.find(timezoneInfo => timezoneInfo.id === userTimezone);
+    } else if (defaultTimezoneId) {
+      foundTimezone = timezoneList.find(timezoneInfo => timezoneInfo.id === defaultTimezoneId);
+    }
   }
+  return foundTimezone;
 }
 
-export function getTimezoneInfo(timezoneId: string, defaultTimezoneId?: string, userTimezoneByDefault?: boolean): Observable<TimezoneInfo> {
-  return getTimezones().pipe(
-    mergeMap((timezoneList) => {
-      let foundTimezone = timezoneList.find(timezoneInfo => timezoneInfo.id === timezoneId);
-      if (!foundTimezone) {
-        if (userTimezoneByDefault) {
-          return getDefaultTimezone().pipe(
-            map((userTimezone) => {
-              return timezoneList.find(timezoneInfo => timezoneInfo.id === userTimezone);
-            })
-          );
-        } else if (defaultTimezoneId) {
-          foundTimezone = timezoneList.find(timezoneInfo => timezoneInfo.id === defaultTimezoneId);
-        }
-      }
-      return of(foundTimezone);
-    })
-  );
+export function getDefaultTimezone(): string {
+  if (!defaultTimezone) {
+    defaultTimezone = monentTz.tz.guess();
+  }
+  return defaultTimezone;
 }
 
-export function getDefaultTimezone(): Observable<string> {
-  if (defaultTimezone) {
-    return of(defaultTimezone);
+export function getCurrentTime(tz?: string): moment_.Moment {
+  if (tz) {
+    return moment().tz(tz);
   } else {
-    return from(import('moment-timezone')).pipe(
-      map((monentTz) => {
-        return monentTz.tz.guess();
-      }),
-      tap((zone) => {
-        defaultTimezone = zone;
-      })
-    );
+    return moment();
   }
 }
+
+export function getTimezone(tz: string): moment_.Moment {
+    return moment.tz(tz);
+}