diff --git a/web/src/components/filter/ReviewFilterGroup.tsx b/web/src/components/filter/ReviewFilterGroup.tsx
index 0ebb00a20..12434f67e 100644
--- a/web/src/components/filter/ReviewFilterGroup.tsx
+++ b/web/src/components/filter/ReviewFilterGroup.tsx
@@ -10,8 +10,7 @@ import {
   DropdownMenuSeparator,
   DropdownMenuTrigger,
 } from "../ui/dropdown-menu";
-import { Calendar } from "../ui/calendar";
-import { ReviewFilter } from "@/types/review";
+import { ReviewFilter, ReviewSummary } from "@/types/review";
 import { getEndOfDayTimestamp } from "@/utils/dateUtil";
 import { useFormattedTimestamp } from "@/hooks/use-date-utils";
 import { FaCalendarAlt, FaFilter, FaVideo } from "react-icons/fa";
@@ -20,15 +19,18 @@ import { Drawer, DrawerContent, DrawerTrigger } from "../ui/drawer";
 import { Switch } from "../ui/switch";
 import { Label } from "../ui/label";
 import FilterCheckBox from "./FilterCheckBox";
+import ReviewActivityCalendar from "../overlay/ReviewActivityCalendar";
 
 const ATTRIBUTES = ["amazon", "face", "fedex", "license_plate", "ups"];
 
 type ReviewFilterGroupProps = {
+  reviewSummary?: ReviewSummary;
   filter?: ReviewFilter;
   onUpdateFilter: (filter: ReviewFilter) => void;
 };
 
 export default function ReviewFilterGroup({
+  reviewSummary,
   filter,
   onUpdateFilter,
 }: ReviewFilterGroupProps) {
@@ -102,6 +104,7 @@ export default function ReviewFilterGroup({
         }}
       />
       <CalendarFilterButton
+        reviewSummary={reviewSummary}
         day={
           filter?.after == undefined ? undefined : new Date(filter.after * 1000)
         }
@@ -273,22 +276,17 @@ function CamerasFilterButton({
 }
 
 type CalendarFilterButtonProps = {
+  reviewSummary?: ReviewSummary;
   day?: Date;
   updateSelectedDay: (day?: Date) => void;
 };
 function CalendarFilterButton({
+  reviewSummary,
   day,
   updateSelectedDay,
 }: CalendarFilterButtonProps) {
-  const disabledDates = useMemo(() => {
-    const tomorrow = new Date();
-    tomorrow.setHours(tomorrow.getHours() + 24, -1, 0, 0);
-    const future = new Date();
-    future.setFullYear(tomorrow.getFullYear() + 10);
-    return { from: tomorrow, to: future };
-  }, []);
   const selectedDate = useFormattedTimestamp(
-    day == undefined ? 0 : day?.getTime() / 1000,
+    day == undefined ? 0 : day?.getTime() / 1000 + 1,
     "%b %-d",
   );
 
@@ -302,14 +300,10 @@ function CalendarFilterButton({
   );
   const content = (
     <>
-      <Calendar
-        mode="single"
-        disabled={disabledDates}
-        selected={day}
-        showOutsideDays={false}
-        onSelect={(day) => {
-          updateSelectedDay(day);
-        }}
+      <ReviewActivityCalendar
+        reviewSummary={reviewSummary}
+        selectedDay={day}
+        onSelect={updateSelectedDay}
       />
       <DropdownMenuSeparator />
       <div className="p-2 flex justify-center items-center">
diff --git a/web/src/components/overlay/ReviewActivityCalendar.tsx b/web/src/components/overlay/ReviewActivityCalendar.tsx
new file mode 100644
index 000000000..009339fc8
--- /dev/null
+++ b/web/src/components/overlay/ReviewActivityCalendar.tsx
@@ -0,0 +1,78 @@
+import { ReviewSummary } from "@/types/review";
+import { Calendar } from "../ui/calendar";
+import { useMemo } from "react";
+import { FaCircle } from "react-icons/fa";
+
+type ReviewActivityCalendarProps = {
+  reviewSummary?: ReviewSummary;
+  selectedDay?: Date;
+  onSelect: (day?: Date) => void;
+};
+export default function ReviewActivityCalendar({
+  reviewSummary,
+  selectedDay,
+  onSelect,
+}: ReviewActivityCalendarProps) {
+  const disabledDates = useMemo(() => {
+    const tomorrow = new Date();
+    tomorrow.setHours(tomorrow.getHours() + 24, -1, 0, 0);
+    const future = new Date();
+    future.setFullYear(tomorrow.getFullYear() + 10);
+    return { from: tomorrow, to: future };
+  }, []);
+
+  return (
+    <Calendar
+      mode="single"
+      disabled={disabledDates}
+      showOutsideDays={false}
+      selected={selectedDay}
+      onSelect={onSelect}
+      components={{
+        DayContent: (date) => (
+          <ReviewActivityDay reviewSummary={reviewSummary} day={date.date} />
+        ),
+      }}
+    />
+  );
+}
+
+type ReviewActivityDayProps = {
+  reviewSummary?: ReviewSummary;
+  day: Date;
+};
+function ReviewActivityDay({ reviewSummary, day }: ReviewActivityDayProps) {
+  const dayActivity = useMemo(() => {
+    if (!reviewSummary) {
+      return "none";
+    }
+
+    const allActivity =
+      reviewSummary[
+        `${day.getFullYear()}-${("0" + (day.getMonth() + 1)).slice(-2)}-${("0" + day.getDate()).slice(-2)}`
+      ];
+
+    if (!allActivity) {
+      return "none";
+    }
+
+    if (allActivity.total_alert > allActivity.reviewed_alert) {
+      return "alert";
+    } else if (allActivity.total_detection > allActivity.reviewed_detection) {
+      return "detection";
+    } else {
+      return "none";
+    }
+  }, [reviewSummary, day]);
+
+  return (
+    <div className="flex flex-col justify-center items-center">
+      {day.getDate()}
+      {dayActivity != "none" && (
+        <FaCircle
+          className={`size-2 ${dayActivity == "alert" ? "fill-severity_alert" : "fill-severity_detection"}`}
+        />
+      )}
+    </div>
+  );
+}
diff --git a/web/src/views/events/EventView.tsx b/web/src/views/events/EventView.tsx
index eaae92a0f..b78a45703 100644
--- a/web/src/views/events/EventView.tsx
+++ b/web/src/views/events/EventView.tsx
@@ -238,7 +238,11 @@ export default function EventView({
         </ToggleGroup>
 
         {selectedReviews.length <= 0 ? (
-          <ReviewFilterGroup filter={filter} onUpdateFilter={updateFilter} />
+          <ReviewFilterGroup
+            reviewSummary={reviewSummary}
+            filter={filter}
+            onUpdateFilter={updateFilter}
+          />
         ) : (
           <ReviewActionGroup
             selectedReviews={selectedReviews}