diff --git a/cli/src/agent/messageConverter.test.ts b/cli/src/agent/messageConverter.test.ts
index d32fa523..3ba4db89 100644
--- a/cli/src/agent/messageConverter.test.ts
+++ b/cli/src/agent/messageConverter.test.ts
@@ -89,10 +89,11 @@ describe('convertAgentMessage', () => {
             totalTokens: 13_892,
             contextTokens: 13_879,
             contextWindow: 65_536
-        });
+        }, 'kimi-k2.5');
 
         expect(converted).toEqual({
             type: 'token_count',
+            model: 'kimi-k2.5',
             info: {
                 total: {
                     inputTokens: 8119,
@@ -106,6 +107,19 @@ describe('convertAgentMessage', () => {
             }
         });
     });
+
+    it('stamps unknown usage models explicitly', () => {
+        const converted = convertAgentMessage({
+            type: 'usage',
+            inputTokens: 10,
+            outputTokens: 2
+        });
+
+        expect(converted).toMatchObject({
+            type: 'token_count',
+            model: null
+        });
+    });
     it('returns null instead of echoing an unrecognized message shape', () => {
         // Unreachable through the type system, but callers forward any non-null
         // result straight into the chat stream — so the runtime contract has to
diff --git a/cli/src/agent/messageConverter.ts b/cli/src/agent/messageConverter.ts
index 034f7dad..acd85134 100644
--- a/cli/src/agent/messageConverter.ts
+++ b/cli/src/agent/messageConverter.ts
@@ -6,6 +6,7 @@ export type CodexMessage =
     | { type: 'reasoning'; message: string; id: string }
     | {
         type: 'token_count';
+        model: string | null;
         info: {
             total: {
                 inputTokens: number;
@@ -36,7 +37,7 @@ export type CodexMessage =
     | { type: 'plan'; entries: PlanItem[] }
     | { type: 'error'; message: string };
 
-export function convertAgentMessage(message: AgentMessage): CodexMessage | null {
+export function convertAgentMessage(message: AgentMessage, model?: string | null): CodexMessage | null {
     switch (message.type) {
         case 'text':
             return { type: 'message', message: message.text };
@@ -48,6 +49,7 @@ export function convertAgentMessage(message: AgentMessage): CodexMessage | null
         case 'usage':
             return {
                 type: 'token_count',
+                model: typeof model === 'string' && model.trim() ? model.trim() : null,
                 info: {
                     total: {
                         inputTokens: message.inputTokens,
diff --git a/cli/src/agent/runners/runAgentSession.ts b/cli/src/agent/runners/runAgentSession.ts
index a4e10046..efd33c28 100644
--- a/cli/src/agent/runners/runAgentSession.ts
+++ b/cli/src/agent/runners/runAgentSession.ts
@@ -188,7 +188,8 @@ export async function runAgentSession(opts: {
 
             try {
                 await backend.prompt(agentSessionId, promptContent, (message) => {
-                    const converted = convertAgentMessage(message);
+                    const model = backend.getSessionModelsMetadata?.(agentSessionId)?.currentModelId;
+                    const converted = convertAgentMessage(message, model);
                     if (converted) {
                         session.sendAgentMessage(converted);
                     }
diff --git a/cli/src/codex/codexLocalLauncher.test.ts b/cli/src/codex/codexLocalLauncher.test.ts
index 10e286fa..97e78fc0 100644
--- a/cli/src/codex/codexLocalLauncher.test.ts
+++ b/cli/src/codex/codexLocalLauncher.test.ts
@@ -373,9 +373,9 @@ describe('codexLocalLauncher', () => {
         });
     });
 
-    it('tracks explicit and default reasoning effort from local turn context', async () => {
+    it('tracks local turn context and stamps its model on usage', async () => {
         const transcriptPath = await writeTranscriptMeta('codex-turn-context.jsonl', 'codex-thread-effort');
-        const { session, getModelReasoningEffort, getModelReasoningEffortUpdates } = createSessionStub('default');
+        const { session, agentMessages, getModelReasoningEffort, getModelReasoningEffortUpdates } = createSessionStub('default');
         let releaseRunBarrier: (() => void) | undefined;
         harness.runBarrier = new Promise((resolve) => {
             releaseRunBarrier = resolve;
@@ -393,13 +393,13 @@ describe('codexLocalLauncher', () => {
                 type: 'turn_context',
                 payload: { effort: 'max' }
             }),
-            JSON.stringify({
-                type: 'event_msg',
-                payload: { type: 'token_count', info: {} }
-            }),
             JSON.stringify({
                 type: 'turn_context',
                 payload: { model: 'gpt-5.4' }
+            }),
+            JSON.stringify({
+                type: 'event_msg',
+                payload: { type: 'token_count', info: {} }
             })
         ].join('\n') + '\n');
         await wait(700);
@@ -409,6 +409,10 @@ describe('codexLocalLauncher', () => {
 
         expect(getModelReasoningEffortUpdates()).toEqual(['max', null]);
         expect(getModelReasoningEffort()).toBeNull();
+        expect(agentMessages).toContainEqual(expect.objectContaining({
+            type: 'token_count',
+            model: 'gpt-5.4'
+        }));
     });
 
     it('renders nested Code Mode plans and commands without their covered exec wrapper', async () => {
diff --git a/cli/src/codex/codexLocalLauncher.ts b/cli/src/codex/codexLocalLauncher.ts
index 6c5a21b8..43b00921 100644
--- a/cli/src/codex/codexLocalLauncher.ts
+++ b/cli/src/codex/codexLocalLauncher.ts
@@ -36,6 +36,16 @@ function extractTurnContextReasoningEffort(event: CodexSessionEvent): ReasoningE
     return effort.trim().toLowerCase();
 }
 
+function extractTurnContextModel(event: CodexSessionEvent): string | null | undefined {
+    if (event.type !== 'turn_context' || !event.payload || typeof event.payload !== 'object') {
+        return undefined;
+    }
+    const model = (event.payload as Record<string, unknown>).model;
+    if (model === null) return null;
+    if (typeof model !== 'string' || !model.trim()) return undefined;
+    return model.trim();
+}
+
 export async function codexLocalLauncher(session: CodexSession): Promise<'switch' | 'exit'> {
     const resumeSessionId = session.sessionId;
     let primarySessionId = resumeSessionId;
@@ -47,6 +57,7 @@ export async function codexLocalLauncher(session: CodexSession): Promise<'switch
     let transcriptLocator: CodexTranscriptLocator | null = null;
     let scannerTranscriptPath: string | null = null;
     let scannerReplayedExistingHistory = false;
+    let transcriptModel: string | null = null;
     const pendingPlansByTurnId = new Map<string, ProposedPlanMessage>();
     const pendingExecWrappers = new Map<string, PendingExecWrapper>();
     const toolHookBridge = new CodexToolHookBridge();
@@ -203,6 +214,10 @@ export async function codexLocalLauncher(session: CodexSession): Promise<'switch
                 session.onSessionFound(sessionId);
             },
             onEvent: (event, context) => {
+                const observedModel = extractTurnContextModel(event);
+                if (observedModel !== undefined) {
+                    transcriptModel = observedModel;
+                }
                 const observedReasoningEffort = extractTurnContextReasoningEffort(event);
                 if (observedReasoningEffort !== undefined) {
                     session.setModelReasoningEffort(observedReasoningEffort);
@@ -245,15 +260,16 @@ export async function codexLocalLauncher(session: CodexSession): Promise<'switch
                         const scopedMessage = message.type !== 'token_count'
                             ? message
                             : context.replayedHistory
-                                ? { ...message, hapiUsageScope: 'imported-history' }
+                                ? { ...message, model: transcriptModel, hapiUsageScope: 'imported-history' }
                                 : primarySessionId
                                     ? {
                                         ...message,
+                                        model: transcriptModel,
                                         threadId: primarySessionId,
                                         thread_id: primarySessionId,
                                         hapiUsageScope: 'managed'
                                     }
-                                    : message;
+                                    : { ...message, model: transcriptModel };
                         session.sendAgentMessage(scopedMessage);
                     }
                 }
diff --git a/cli/src/codex/codexRemoteLauncher.ts b/cli/src/codex/codexRemoteLauncher.ts
index b6d52767..3cbc12f5 100644
--- a/cli/src/codex/codexRemoteLauncher.ts
+++ b/cli/src/codex/codexRemoteLauncher.ts
@@ -681,6 +681,7 @@ class CodexRemoteLauncher extends RemoteLauncherBase {
         let scheduleReadyAfterTurn: (() => void) | null = null;
         let clearReadyAfterTurnTimer: (() => void) | null = null;
         let turnInFlight = false;
+        let usageModel: string | null = null;
         let allowAnonymousTerminalEvent = false;
         let invalidThreadId: string | null = null;
         let childAgentActivityInCurrentTurn = false;
@@ -2874,6 +2875,7 @@ class CodexRemoteLauncher extends RemoteLauncherBase {
                 const threadId = eventThreadId ?? this.currentThreadId;
                 session.sendAgentMessage({
                     ...addCodexEventScope(msg, 'parent', threadId),
+                    model: asString(msg.model) ?? usageModel,
                     id: randomUUID()
                 });
             }
@@ -3784,6 +3786,9 @@ class CodexRemoteLauncher extends RemoteLauncherBase {
                     ...message.mode,
                     model: session.getModel() ?? message.mode.model
                 };
+                usageModel = typeof mode.model === 'string' && mode.model.trim()
+                    ? mode.model.trim()
+                    : null;
                 const shouldSendCollaborationMode = supportsTurnCollaborationMode
                     && Boolean(mode.collaborationMode);
                 const clientUserMessageId = message.items
diff --git a/cli/src/cursor/cursorAcpRemoteLauncher.ts b/cli/src/cursor/cursorAcpRemoteLauncher.ts
index de30a4af..e0d35a9d 100644
--- a/cli/src/cursor/cursorAcpRemoteLauncher.ts
+++ b/cli/src/cursor/cursorAcpRemoteLauncher.ts
@@ -458,7 +458,7 @@ class CursorAcpRemoteLauncher extends RemoteLauncherBase {
     }
 
     private handleAgentMessage(message: AgentMessage): void {
-        const converted = convertAgentMessage(message);
+        const converted = convertAgentMessage(message, this.currentBackendModel);
         if (converted) {
             this.session.sendAgentMessage(converted);
         }
diff --git a/cli/src/cursor/cursorLegacyRemoteLauncher.ts b/cli/src/cursor/cursorLegacyRemoteLauncher.ts
index e0448c47..3d4437f1 100644
--- a/cli/src/cursor/cursorLegacyRemoteLauncher.ts
+++ b/cli/src/cursor/cursorLegacyRemoteLauncher.ts
@@ -195,7 +195,7 @@ class CursorRemoteLauncher extends RemoteLauncherBase {
                     } else if (event.type === 'assistant' || event.type === 'tool_call' || event.type === 'result') {
                         const agentMsg = convertCursorEventToAgentMessage(event);
                         if (agentMsg) {
-                            const codexMsg = convertAgentMessage(agentMsg);
+                            const codexMsg = convertAgentMessage(agentMsg, session.model);
                             if (codexMsg) {
                                 session.sendAgentMessage(codexMsg);
                             }
diff --git a/cli/src/grok/grokRemoteLauncher.ts b/cli/src/grok/grokRemoteLauncher.ts
index 54acb67c..c0da98b9 100644
--- a/cli/src/grok/grokRemoteLauncher.ts
+++ b/cli/src/grok/grokRemoteLauncher.ts
@@ -384,7 +384,7 @@ class GrokRemoteLauncher extends RemoteLauncherBase {
     }
 
     private handleAgentMessage(message: AgentMessage): void {
-        const converted = convertAgentMessage(message)
+        const converted = convertAgentMessage(message, this.currentBackendModel)
         if (converted) this.session.sendAgentMessage(converted)
 
         switch (message.type) {
diff --git a/cli/src/kimi/kimiLocalLauncher.ts b/cli/src/kimi/kimiLocalLauncher.ts
index 49912ba5..bcd6d8f2 100644
--- a/cli/src/kimi/kimiLocalLauncher.ts
+++ b/cli/src/kimi/kimiLocalLauncher.ts
@@ -42,7 +42,7 @@ export async function kimiLocalLauncher(
                     if (shuttingDown) {
                         return;
                     }
-                    const converted = convertKimiWireEvent(event);
+                    const converted = convertKimiWireEvent(event, session.getModel() ?? opts.model);
                     if (!converted) {
                         return;
                     }
diff --git a/cli/src/kimi/kimiRemoteLauncher.ts b/cli/src/kimi/kimiRemoteLauncher.ts
index 1bcd8738..36e67931 100644
--- a/cli/src/kimi/kimiRemoteLauncher.ts
+++ b/cli/src/kimi/kimiRemoteLauncher.ts
@@ -222,7 +222,7 @@ class KimiRemoteLauncher extends RemoteLauncherBase {
     }
 
     private handleAgentMessage(message: AgentMessage): void {
-        const converted = convertAgentMessage(message);
+        const converted = convertAgentMessage(message, this.currentBackendModel);
         if (converted) {
             this.session.sendAgentMessage(converted);
         }
diff --git a/cli/src/kimi/utils/kimiWireScanner.test.ts b/cli/src/kimi/utils/kimiWireScanner.test.ts
index 660255aa..45b8a9e8 100644
--- a/cli/src/kimi/utils/kimiWireScanner.test.ts
+++ b/cli/src/kimi/utils/kimiWireScanner.test.ts
@@ -77,9 +77,10 @@ describe('convertKimiWireEvent', () => {
                 uuid: 's1',
                 usage: { inputOther: 100, output: 20, inputCacheRead: 50, inputCacheCreation: 10 }
             }
-        })).toEqual({
+        }, 'kimi-k2.5')).toEqual({
             message: {
                 type: 'token_count',
+                model: 'kimi-k2.5',
                 info: { total: { inputTokens: 160, outputTokens: 20, cachedInputTokens: 50 } }
             }
         });
diff --git a/cli/src/kimi/utils/kimiWireScanner.ts b/cli/src/kimi/utils/kimiWireScanner.ts
index 24e3a2d8..1a644ec6 100644
--- a/cli/src/kimi/utils/kimiWireScanner.ts
+++ b/cli/src/kimi/utils/kimiWireScanner.ts
@@ -65,7 +65,7 @@ function extractInputText(input: unknown): string | null {
  * Everything else (metadata, config.update, llm.request, usage.record,
  * step.begin, plan_mode.*, …) is ignored.
  */
-export function convertKimiWireEvent(event: KimiWireEvent): KimiWireConversion | null {
+export function convertKimiWireEvent(event: KimiWireEvent, model?: string | null): KimiWireConversion | null {
     if (event.type === 'turn.prompt' || event.type === 'turn.steer') {
         const origin = asRecord(event.origin);
         if (asString(origin?.kind) !== 'user') {
@@ -149,6 +149,7 @@ export function convertKimiWireEvent(event: KimiWireEvent): KimiWireConversion |
         return {
             message: {
                 type: 'token_count',
+                model: typeof model === 'string' && model.trim() ? model.trim() : null,
                 info: {
                     total: {
                         inputTokens: inputOther + cacheRead + cacheCreation,
diff --git a/cli/src/opencode/opencodeRemoteLauncher.ts b/cli/src/opencode/opencodeRemoteLauncher.ts
index 3dea38e0..425ea7c7 100644
--- a/cli/src/opencode/opencodeRemoteLauncher.ts
+++ b/cli/src/opencode/opencodeRemoteLauncher.ts
@@ -767,7 +767,7 @@ class OpencodeRemoteLauncher extends RemoteLauncherBase {
     }
 
     private handleAgentMessage(message: AgentMessage): void {
-        const converted = convertAgentMessage(message);
+        const converted = convertAgentMessage(message, this.currentBackendModel);
         if (converted) {
             this.session.sendAgentMessage(converted);
         }
diff --git a/cli/src/pi/loop.ts b/cli/src/pi/loop.ts
index 0b1210b5..82be9348 100644
--- a/cli/src/pi/loop.ts
+++ b/cli/src/pi/loop.ts
@@ -326,7 +326,7 @@ async function publishPiTurnUsage(
     const usageMessage = convertPiTurnUsage(event, contextUsage);
     if (!usageMessage) return;
 
-    const converted = convertAgentMessage(usageMessage);
+    const converted = convertAgentMessage(usageMessage, session.currentModel);
     if (converted) session.sendAgentMessage(converted);
 }
 
@@ -362,7 +362,7 @@ export function wireTransportEvents(
         const accumulated = assistantMessageAccumulator.handleEvent(event);
         if (accumulated.length > 0) {
             for (const msg of accumulated) {
-                const converted = convertAgentMessage(msg);
+                const converted = convertAgentMessage(msg, session.currentModel);
                 if (converted) session.sendAgentMessage(converted);
             }
         }
@@ -371,7 +371,7 @@ export function wireTransportEvents(
         if (event.type !== 'message_start' && event.type !== 'message_update' && event.type !== 'message_end') {
             const messages = convertPiEvent(event);
             for (const msg of messages) {
-                const converted = convertAgentMessage(msg);
+                const converted = convertAgentMessage(msg, session.currentModel);
                 if (converted) session.sendAgentMessage(converted);
             }
         }
diff --git a/hub/src/sync/usageService.test.ts b/hub/src/sync/usageService.test.ts
index 2b8ee125..a0d673fd 100644
--- a/hub/src/sync/usageService.test.ts
+++ b/hub/src/sync/usageService.test.ts
@@ -2,8 +2,18 @@ import { describe, expect, it } from 'bun:test'
 import { Store } from '../store'
 import { getUsageSummary } from './usageService'
 
-function addAgentMessage(store: Store, sessionId: string, content: unknown): void {
-    store.messages.addMessage(sessionId, { role: 'agent', content })
+function addAgentMessage(store: Store, sessionId: string, content: unknown, createdAt?: number): void {
+    if (createdAt === undefined) {
+        store.messages.addMessage(sessionId, { role: 'agent', content })
+        return
+    }
+    store.messages.copyMessageToSession(sessionId, {
+        content: { role: 'agent', content },
+        createdAt,
+        localId: null,
+        invokedAt: createdAt,
+        scheduledAt: null
+    })
 }
 
 describe('usage service', () => {
@@ -172,6 +182,85 @@ describe('usage service', () => {
         expect(result.totals.requests).toBe(1)
         expect(result.totals.totalTokens).toBe(110)
         expect(result.totals.uncachedTokens).toBe(30)
+        expect(result.byModel).toEqual([expect.objectContaining({ key: 'unknown' })])
+        store.close()
+    })
+
+    it('preserves event-level models across model switches and epoch rebuilds', () => {
+        const store = new Store(':memory:')
+        const session = store.sessions.getOrCreateSession(
+            'codex-model-switch-test',
+            { path: '/tmp', host: 'test', flavor: 'codex' },
+            null,
+            'default',
+            'initial-model'
+        )
+
+        addAgentMessage(store, session.id, {
+            type: 'codex',
+            data: {
+                type: 'token_count',
+                model: 'old-model',
+                thread_id: 'thread-1',
+                turn_id: 'turn-1',
+                info: {
+                    total_token_usage: { input_tokens: 100, output_tokens: 10 },
+                    last_token_usage: { input_tokens: 100, output_tokens: 10 }
+                }
+            }
+        })
+        addAgentMessage(store, session.id, {
+            type: 'codex',
+            data: {
+                type: 'token_count',
+                model: 'new-model',
+                thread_id: 'thread-1',
+                turn_id: 'turn-2',
+                info: {
+                    total_token_usage: { input_tokens: 140, output_tokens: 15 },
+                    last_token_usage: { input_tokens: 40, output_tokens: 5 }
+                }
+            }
+        })
+        store.sessions.setSessionModel(session.id, 'latest-session-model', 'default')
+
+        const expectedModels = [
+            expect.objectContaining({ key: 'old-model', totalTokens: 110 }),
+            expect.objectContaining({ key: 'new-model', totalTokens: 45 })
+        ]
+        expect(getUsageSummary(store, 'default', 'all').byModel).toEqual(expectedModels)
+
+        store.messages.bumpMessageEpoch(session.id)
+        expect(getUsageSummary(store, 'default', 'all').byModel).toEqual(expectedModels)
+        store.close()
+    })
+
+    it('buckets daily usage using positive and negative viewer offsets', () => {
+        const store = new Store(':memory:')
+        const session = store.sessions.getOrCreateSession(
+            'timezone-usage-test',
+            { path: '/tmp', host: 'test', flavor: 'claude' },
+            null,
+            'default'
+        )
+        const usage = (id: string) => ({
+            type: 'output',
+            data: {
+                type: 'assistant',
+                message: { id, usage: { input_tokens: 10, output_tokens: 2 } }
+            }
+        })
+        addAgentMessage(store, session.id, usage('after-utc-midnight'), Date.parse('2026-01-15T00:30:00Z'))
+        addAgentMessage(store, session.id, usage('before-utc-midnight'), Date.parse('2026-01-15T23:30:00Z'))
+
+        expect(getUsageSummary(store, 'default', 'all', 60).daily.map((row) => row.key)).toEqual([
+            '2026-01-14',
+            '2026-01-15'
+        ])
+        expect(getUsageSummary(store, 'default', 'all', -60).daily.map((row) => row.key)).toEqual([
+            '2026-01-15',
+            '2026-01-16'
+        ])
         store.close()
     })
 
diff --git a/hub/src/sync/usageService.ts b/hub/src/sync/usageService.ts
index fcee6398..f6786e3a 100644
--- a/hub/src/sync/usageService.ts
+++ b/hub/src/sync/usageService.ts
@@ -31,10 +31,6 @@ function sessionAgent(session: StoredSession): string {
     return typeof flavor === 'string' && flavor.trim() ? flavor.trim() : 'unknown'
 }
 
-function sessionModel(session: StoredSession): string | null {
-    return typeof session.model === 'string' && session.model.trim() ? session.model.trim() : null
-}
-
 function parseUsageEvent(session: StoredSession, message: StoredMessage): UsageEvent | null {
     const envelope = asRecord(message.content)
     if (envelope?.role !== 'agent') return null
@@ -58,7 +54,7 @@ function parseUsageEvent(session: StoredSession, message: StoredMessage): UsageE
         const providerId = typeof assistant?.id === 'string' ? assistant.id : message.id
         const model = typeof assistant?.model === 'string' && assistant.model.trim()
             ? assistant.model.trim()
-            : sessionModel(session)
+            : null
         return {
             sessionId: session.id,
             sourceKey: `claude|${providerId}`,
@@ -124,6 +120,9 @@ function parseUsageEvent(session: StoredSession, message: StoredMessage): UsageE
             : typeof data.turn_id === 'string'
                 ? data.turn_id
                 : ''
+        const model = typeof data.model === 'string' && data.model.trim()
+            ? data.model.trim()
+            : null
         return {
             sessionId: session.id,
             sourceKey: isCumulative
@@ -141,7 +140,7 @@ function parseUsageEvent(session: StoredSession, message: StoredMessage): UsageE
             sourceSeq: message.seq,
             createdAt: message.createdAt,
             agent,
-            model: sessionModel(session),
+            model,
             kind: isCumulative ? 'cumulative' : 'delta',
             inputTokens,
             outputTokens,
@@ -225,11 +224,16 @@ function toBucket(key: string, totals: Totals): UsageSummaryBucket {
     return { key, ...totals }
 }
 
-function dayKey(timestamp: number): string {
-    return new Date(timestamp).toISOString().slice(0, 10)
+function dayKey(timestamp: number, timezoneOffset: number): string {
+    return new Date(timestamp - timezoneOffset * 60_000).toISOString().slice(0, 10)
 }
 
-export function getUsageSummary(store: Store, namespace: string, range: string | undefined): UsageSummaryResponse {
+export function getUsageSummary(
+    store: Store,
+    namespace: string,
+    range: string | undefined,
+    timezoneOffset: number = 0
+): UsageSummaryResponse {
     const sessions = store.sessions.getSessionsByNamespace(namespace)
     // This is intentionally lazy. Existing HAPI databases have no usage table;
     // the first dashboard request backfills history, while later requests only
@@ -289,9 +293,10 @@ export function getUsageSummary(store: Store, namespace: string, range: string |
             ? inputTokens + cacheReadTokens + cacheCreationTokens
             : inputTokens
         addTotals(totals, normalizedInputTokens, outputTokens, cacheReadTokens, cacheCreationTokens)
-        const dailyTotals = daily.get(dayKey(event.createdAt)) ?? emptyTotals()
+        const eventDayKey = dayKey(event.createdAt, timezoneOffset)
+        const dailyTotals = daily.get(eventDayKey) ?? emptyTotals()
         addTotals(dailyTotals, normalizedInputTokens, outputTokens, cacheReadTokens, cacheCreationTokens)
-        daily.set(dayKey(event.createdAt), dailyTotals)
+        daily.set(eventDayKey, dailyTotals)
         const agentTotals = byAgent.get(event.agent) ?? emptyTotals()
         addTotals(agentTotals, normalizedInputTokens, outputTokens, cacheReadTokens, cacheCreationTokens)
         byAgent.set(event.agent, agentTotals)
diff --git a/hub/src/web/routes/usage.test.ts b/hub/src/web/routes/usage.test.ts
index 6a386dee..8833da74 100644
--- a/hub/src/web/routes/usage.test.ts
+++ b/hub/src/web/routes/usage.test.ts
@@ -42,4 +42,20 @@ describe('GET /api/usage/summary', () => {
             store.close()
         }
     })
+
+    it('validates positive and negative timezone offset bounds', async () => {
+        const store = new Store(':memory:')
+        try {
+            for (const offset of [-840, 840]) {
+                const response = await createApp(store, 'default').request(`/api/usage/summary?timezoneOffset=${offset}`)
+                expect(response.status).toBe(200)
+            }
+            for (const offset of [-841, 841, 1.5]) {
+                const response = await createApp(store, 'default').request(`/api/usage/summary?timezoneOffset=${offset}`)
+                expect(response.status).toBe(400)
+            }
+        } finally {
+            store.close()
+        }
+    })
 })
diff --git a/hub/src/web/routes/usage.ts b/hub/src/web/routes/usage.ts
index 73c6fc17..8f81219c 100644
--- a/hub/src/web/routes/usage.ts
+++ b/hub/src/web/routes/usage.ts
@@ -12,7 +12,12 @@ export function createUsageRoutes(store: Store): Hono<WebAppEnv> {
             return c.json({ error: 'Usage summary is only available to the hub owner' }, 403)
         }
         const range = c.req.query('range')
-        const response: UsageSummaryResponse = getUsageSummary(store, c.get('namespace'), range)
+        const timezoneOffsetParam = c.req.query('timezoneOffset')
+        const timezoneOffset = timezoneOffsetParam === undefined ? 0 : Number(timezoneOffsetParam)
+        if (!Number.isInteger(timezoneOffset) || timezoneOffset < -840 || timezoneOffset > 840) {
+            return c.json({ error: 'timezoneOffset must be an integer between -840 and 840' }, 400)
+        }
+        const response: UsageSummaryResponse = getUsageSummary(store, c.get('namespace'), range, timezoneOffset)
         c.header('Cache-Control', 'no-store')
         return c.json(response)
     })
diff --git a/web/src/api/client.ts b/web/src/api/client.ts
index d02cbbe1..bd93961c 100644
--- a/web/src/api/client.ts
+++ b/web/src/api/client.ts
@@ -648,8 +648,15 @@ export class ApiClient {
         return await this.request<SqliteStorageUsageResponse>('/api/storage/sqlite')
     }
 
-    async getUsageSummary(range: '7d' | '30d' | 'all' = '7d'): Promise<UsageSummaryResponse> {
-        return await this.request<UsageSummaryResponse>(`/api/usage/summary?range=${encodeURIComponent(range)}`)
+    async getUsageSummary(
+        range: '7d' | '30d' | 'all' = '7d',
+        timezoneOffset: number = new Date().getTimezoneOffset()
+    ): Promise<UsageSummaryResponse> {
+        const params = new URLSearchParams({
+            range,
+            timezoneOffset: String(timezoneOffset)
+        })
+        return await this.request<UsageSummaryResponse>(`/api/usage/summary?${params.toString()}`)
     }
 
     async listMachineDirectory(
diff --git a/web/src/lib/query-keys.ts b/web/src/lib/query-keys.ts
index ec40c254..a48ac53b 100644
--- a/web/src/lib/query-keys.ts
+++ b/web/src/lib/query-keys.ts
@@ -4,7 +4,7 @@ export const queryKeys = {
     messages: (sessionId: string) => ['messages', sessionId] as const,
     machines: ['machines'] as const,
     sqliteStorage: ['sqlite-storage'] as const,
-    usageSummary: (range: string) => ['usage-summary', range] as const,
+    usageSummary: (range: string, timezoneOffset: number) => ['usage-summary', range, timezoneOffset] as const,
     machineCodexModels: (machineId: string) => ['machine-codex-models', machineId] as const,
     gitStatus: (sessionId: string) => ['git-status', sessionId] as const,
     sessionFiles: (sessionId: string, query: string) => ['session-files', sessionId, query] as const,
diff --git a/web/src/routes/settings/usage.tsx b/web/src/routes/settings/usage.tsx
index 5b1347c0..37774c1b 100644
--- a/web/src/routes/settings/usage.tsx
+++ b/web/src/routes/settings/usage.tsx
@@ -47,11 +47,12 @@ export default function SettingsUsagePage() {
     const { api } = useAppContext()
     const { t } = useTranslation()
     const [range, setRange] = useState<UsageRange>('7d')
+    const [timezoneOffset] = useState(() => new Date().getTimezoneOffset())
     const query = useQuery({
-        queryKey: queryKeys.usageSummary(range),
+        queryKey: queryKeys.usageSummary(range, timezoneOffset),
         queryFn: async () => {
             if (!api) throw new Error('API unavailable')
-            return await api.getUsageSummary(range)
+            return await api.getUsageSummary(range, timezoneOffset)
         },
         enabled: Boolean(api),
         staleTime: 30_000,