diff --git a/web/js/components/timeline/timeline-coverage/coverage-item-container.js b/web/js/components/timeline/timeline-coverage/coverage-item-container.js
index 3f188c7bef..935147c722 100644
--- a/web/js/components/timeline/timeline-coverage/coverage-item-container.js
+++ b/web/js/components/timeline/timeline-coverage/coverage-item-container.js
@@ -72,7 +72,7 @@ class CoverageItemContainer extends Component {
       dateIntervalStartDates.forEach((dateIntStartDate) => {
         const dateIntTime = new Date(dateIntStartDate).getTime();
         // allow overwriting of subsequent date ranges
-        if (dateIntTime >= startDateTime && dateIntTime < endDateTime) {
+        if (dateIntTime >= startDateTime && dateIntTime <= endDateTime) {
           const dateIntFormatted = dateIntStartDate.toISOString();
           multiCoverageDates[dateIntFormatted] = {
             date: dateIntFormatted,
diff --git a/web/js/components/timeline/timeline-coverage/coverage-item-list.js b/web/js/components/timeline/timeline-coverage/coverage-item-list.js
index 0c797f1f5c..0dd9349b39 100644
--- a/web/js/components/timeline/timeline-coverage/coverage-item-list.js
+++ b/web/js/components/timeline/timeline-coverage/coverage-item-list.js
@@ -262,9 +262,7 @@ class CoverageItemList extends Component {
     const endGreaterThanOrEqualToStartDateLimit = new Date(rangeEnd).getTime() >= startDateLimit.getTime();
     if (startLessThanOrEqualToEndDateLimit && endGreaterThanOrEqualToStartDateLimit) {
       // check layer date array cache and use caches date array if available, if not add date array
-      if (!this.layerDateArrayCache[id]) {
-        this.layerDateArrayCache[id] = {};
-      }
+      this.layerDateArrayCache[id] ??= {};
 
       const layerIdDates = `${appNow.toISOString()}-${frontDate}-${backDate}`;
       if (this.layerDateArrayCache[id][layerIdDates] === undefined) {