add in timeZone trtait and make use of dateFormat

lib/ModelMixins/DiscretelyTimeVaryingMixin.ts

@@ -392,7 +392,9 @@ function DiscretelyTimeVaryingMixin<
 
 namespace DiscretelyTimeVaryingMixin {
   export interface Instance
-    extends InstanceType<ReturnType<typeof DiscretelyTimeVaryingMixin>> {}
+    extends InstanceType<ReturnType<typeof DiscretelyTimeVaryingMixin>> {
+    [x: string]: any;
+  }
 
   export function isMixedInto(model: any): model is Instance {
     return model && model.hasDiscreteTimes;

lib/ReactViews/BottomDock/Timeline/Timeline.jsx

@@ -8,7 +8,7 @@ import JulianDate from "terriajs-cesium/Source/Core/JulianDate";
 import CommonStrata from "../../../Models/Definition/CommonStrata";
 import withControlledVisibility from "../../HOCs/withControlledVisibility";
 import CesiumTimeline from "./CesiumTimeline";
-import { formatDateTime } from "./DateFormats";
+// import { formatDateTime } from "./DateFormats";
 import DateTimePicker from "./DateTimePicker";
 import Styles from "./timeline.scss";
 import TimelineControls from "./TimelineControls";
@@ -76,7 +76,7 @@ class Timeline extends React.Component {
         this.props.terria.timelineStack.top.dateFormat
       );
     } else {
-      console.log(this.props.locale);
+      console.log(catalogItem.timeZone);
       // currentTime = formatDateTime(jsDate, this.props.locale);
       currentTime = dateFormat(jsDate, "isoDate");
     }

lib/ReactViews/Workbench/Controls/DateTimeSelectorSection.tsx

@@ -128,6 +128,13 @@ class DateTimeSelectorSection extends React.Component<IProps, IState> {
     event.stopPropagation();
   }
 
+  getOffsetMinutes(timeZone: string) {
+    const [hoursString, minutesString] = timeZone.split(":");
+    const hours = parseInt(hoursString);
+    const minutes = parseInt(minutesString);
+    return hours * 60 + minutes;
+  }
+
   render() {
     const { t } = this.props;
     let discreteTime;
@@ -145,14 +152,22 @@ class DateTimeSelectorSection extends React.Component<IProps, IState> {
     }
 
     if (isDefined(item.currentDiscreteJulianDate)) {
-      const time = JulianDate.toDate(item.currentDiscreteJulianDate);
+      let time = JulianDate.toDate(item.currentDiscreteJulianDate);
+      if (isDefined(item.timeZone)) {
+        const offset = this.getOffsetMinutes(item.timeZone);
+        const offsetTime = new JulianDate();
+        const adjTime = JulianDate.addMinutes(
+          item.currentDiscreteJulianDate,
+          offset,
+          offsetTime
+        );
+        time = JulianDate.toDate(adjTime);
+      }
+
       if (isDefined(item.dateFormat)) {
         format = item.dateFormat;
         discreteTime = dateFormat(time, item.dateFormat);
       } else {
-        // discreteTime = formatDateTime(time);
-        // we have no idea what the format is, so just use isoDate, introducing time is
-        // adding complexity
         discreteTime = dateFormat(time, "isoDate");
       }
     }

lib/Traits/TraitsClasses/DateTimeTraits.ts

@@ -3,20 +3,21 @@ import primitiveTrait from "../Decorators/primitiveTrait";
 
 export class DateTimeTraits extends ModelTraits {
   @primitiveTrait({
-    type: "boolean",
-    name: "Is UTC Timezone",
+    type: "string",
+    name: "Timezone",
     description:
       "If the DateTime attribute values do not have timezone information" +
-      " (e.g. 2018-01-01T00:00:00), this flag indicates whether the values should be interpreted as UTC time."
+      " (e.g. 2018-01-01T00:00:00), specify the ISO timezone with offset from UTC (e.g. +10:00)"
   })
-  isUTC?: boolean;
+  timeZone?: string;
 
   @primitiveTrait({
     type: "string",
-    name: "Timezone",
+    name: "Date format",
     description:
-      "If the DateTime attribute values do not have timezone information" +
-      " (e.g. 2018-01-01T00:00:00), specify the ISO timezone with offset from UTC (e.g. +10:00)"
+      "See available formats here https://github.com/felixge/node-dateformat"
   })
-  timeZone?: string;
+  dateFormat?: string;
 }
+
+export default DateTimeTraits;

lib/Traits/TraitsClasses/WebMapServiceCatalogItemTraits.ts

@@ -8,7 +8,7 @@ import mixTraits from "../mixTraits";
 import ModelTraits from "../ModelTraits";
 import { traitClass } from "../Trait";
 import CatalogMemberTraits from "./CatalogMemberTraits";
-import { DateTimeTraits } from "./DateTimeTraits";
+import DateTimeTraits from "./DateTimeTraits";
 import DiffableTraits from "./DiffableTraits";
 import ExportWebCoverageServiceTraits from "./ExportWebCoverageServiceTraits";
 import GetCapabilitiesTraits from "./GetCapabilitiesTraits";