diff --git a/site/src/pages/AgentsPage/ConfigureAgentsDialog.tsx b/site/src/pages/AgentsPage/ConfigureAgentsDialog.tsx
index 6077008c97..6635692786 100644
--- a/site/src/pages/AgentsPage/ConfigureAgentsDialog.tsx
+++ b/site/src/pages/AgentsPage/ConfigureAgentsDialog.tsx
@@ -139,21 +139,25 @@ const UserRow: FC<{
 	);
 };
 
-const UsageContent: FC = () => {
+interface UsageContentProps {
+	now?: dayjs.Dayjs;
+}
+
+const UsageContent: FC<UsageContentProps> = ({ now }) => {
 	const [selectedUser, setSelectedUser] =
 		useState<TypesGen.ChatCostUserRollup | null>(null);
 	const [usernameFilter, setUsernameFilter] = useState("");
 	const debouncedUsername = useDebouncedValue(usernameFilter, 300);
 	const [page, setPage] = useState(1);
 	const dateRange = useMemo(() => {
-		const end = dayjs();
+		const end = now ?? dayjs();
 		const start = end.subtract(30, "day");
 		return {
 			startDate: start.toISOString(),
 			endDate: end.toISOString(),
 			rangeLabel: `${start.format("MMM D")} – ${end.format("MMM D, YYYY")}`,
 		};
-	}, []);
+	}, [now]);
 	const offset = (page - 1) * pageSize;
 
 	const usersQuery = useQuery({
@@ -354,6 +358,8 @@ interface ConfigureAgentsDialogProps {
 	canManageChatModelConfigs: boolean;
 	canSetSystemPrompt: boolean;
 	initialSection?: ConfigureAgentsSection;
+	/** Override the current time for date range calculation. Used for deterministic Storybook snapshots. */
+	now?: dayjs.Dayjs;
 }
 
 export const ConfigureAgentsDialog: FC<ConfigureAgentsDialogProps> = ({
@@ -362,6 +368,7 @@ export const ConfigureAgentsDialog: FC<ConfigureAgentsDialogProps> = ({
 	canManageChatModelConfigs,
 	canSetSystemPrompt,
 	initialSection = "behavior",
+	now,
 }) => {
 	const queryClient = useQueryClient();
 
@@ -635,7 +642,7 @@ export const ConfigureAgentsDialog: FC<ConfigureAgentsDialogProps> = ({
 						/>
 					)}
 					{activeSection === "usage" && canManageChatModelConfigs && (
-						<UsageContent />
+						<UsageContent now={now} />
 					)}
 				</div>
 			</DialogContent>
diff --git a/site/src/pages/AgentsPage/UserAnalyticsDialog.stories.tsx b/site/src/pages/AgentsPage/UserAnalyticsDialog.stories.tsx
index 314adf0e6d..5d4753a5f5 100644
--- a/site/src/pages/AgentsPage/UserAnalyticsDialog.stories.tsx
+++ b/site/src/pages/AgentsPage/UserAnalyticsDialog.stories.tsx
@@ -3,7 +3,8 @@ import { withAuthProvider } from "testHelpers/storybook";
 import type { Meta, StoryObj } from "@storybook/react-vite";
 import { API } from "api/api";
 import type * as TypesGen from "api/typesGenerated";
-import { fn, spyOn } from "storybook/test";
+import dayjs from "dayjs";
+import { expect, fn, screen, spyOn, waitFor } from "storybook/test";
 import { UserAnalyticsDialog } from "./UserAnalyticsDialog";
 
 const mockSummary: TypesGen.ChatCostSummary = {
@@ -63,5 +64,11 @@ export const Default: Story = {
 	args: {
 		open: true,
 		onOpenChange: fn(),
+		now: dayjs("2026-03-12T12:00:00Z"),
+	},
+	play: async () => {
+		await waitFor(() => {
+			expect(screen.getByText(/Feb 10\s*–\s*Mar 12, 2026/)).toBeInTheDocument();
+		});
 	},
 };
diff --git a/site/src/pages/AgentsPage/UserAnalyticsDialog.tsx b/site/src/pages/AgentsPage/UserAnalyticsDialog.tsx
index 9794b5c0d5..09e457cf24 100644
--- a/site/src/pages/AgentsPage/UserAnalyticsDialog.tsx
+++ b/site/src/pages/AgentsPage/UserAnalyticsDialog.tsx
@@ -16,8 +16,8 @@ import { useQuery } from "react-query";
 import { ChatCostSummaryView } from "./ChatCostSummaryView";
 import { SectionHeader } from "./SectionHeader";
 
-const createDateRange = () => {
-	const end = dayjs();
+const createDateRange = (now?: dayjs.Dayjs) => {
+	const end = now ?? dayjs();
 	const start = end.subtract(30, "day");
 	return {
 		startDate: start.toISOString(),
@@ -29,14 +29,17 @@ const createDateRange = () => {
 interface UserAnalyticsDialogProps {
 	open: boolean;
 	onOpenChange: (open: boolean) => void;
+	/** Override the current time for date range calculation. Used for deterministic Storybook snapshots. */
+	now?: dayjs.Dayjs;
 }
 
 export const UserAnalyticsDialog: FC<UserAnalyticsDialogProps> = ({
 	open,
 	onOpenChange,
+	now,
 }) => {
 	const { user } = useAuthContext();
-	const dateRange = useMemo(createDateRange, []);
+	const dateRange = useMemo(() => createDateRange(now), [now]);
 
 	const summaryQuery = useQuery({
 		...chatCostSummary(user?.id ?? "me", {