diff --git a/docs/ai/api.md b/docs/ai/api.md
index a8d1eaf..28af62b 100644
--- a/docs/ai/api.md
+++ b/docs/ai/api.md
@@ -107,8 +107,10 @@ Authenticates with the paired `email` + `licenseKey` query parameters and
 validates only that the key belongs to the account (not that the license is
 active/entitled). Returns the user's Blocks with start/end times and the IDs of
 the selected Proclamations (content is fetched separately via
-`/api/v2/proclamations`). Rate limited to 10 requests per minute per IP.
-Failure messages follow the existing v2 shape:
+`/api/v2/proclamations`). Overnight blocks (end clock time before start) are
+supported and flagged with `overnight: true` plus a wrapping `durationMinutes`.
+Rate limited to 10 requests per minute per IP. Failure messages follow the
+existing v2 shape:
 `not-authorized` or `this key doesn't appear to belong to you`.
 
 ---
diff --git a/docs/openapi.yaml b/docs/openapi.yaml
index 9eb3568..bfed06a 100644
--- a/docs/openapi.yaml
+++ b/docs/openapi.yaml
@@ -245,7 +245,9 @@ paths:
         pairing.
 
         Returns every Block with its start/end times and the ordered list of
-        selected Proclamation IDs. Proclamation content is not included; the
+        selected Proclamation IDs. Overnight blocks (an end clock time before
+        the start) are supported and flagged with `overnight: true` and a
+        wrapping `durationMinutes`. Proclamation content is not included; the
         kiosk fetches it separately via `/api/v2/proclamations`.
       operationId: getSchedule
       parameters:
@@ -498,7 +500,17 @@ components:
           format: email
     ScheduleBlock:
       type: object
-      required: [id, startTime, startMinutes, endTime, endMinutes, proclamationIds]
+      required:
+        [
+          id,
+          startTime,
+          startMinutes,
+          endTime,
+          endMinutes,
+          overnight,
+          durationMinutes,
+          proclamationIds
+        ]
       properties:
         id:
           type: string
@@ -521,6 +533,13 @@ components:
           minimum: 0
           maximum: 1440
           description: Minutes from midnight.
+        overnight:
+          type: boolean
+          description: True when the end clock time is at or before the start, i.e. the block crosses midnight.
+        durationMinutes:
+          type: integer
+          minimum: 1
+          description: Block length in minutes. An overnight block counts the wrap past midnight as the next day.
         proclamationIds:
           type: array
           description: IDs of the selected Proclamations, in play order.
diff --git a/src/lib/server/v2-serializers.ts b/src/lib/server/v2-serializers.ts
index 1325e0c..7aa6a74 100644
--- a/src/lib/server/v2-serializers.ts
+++ b/src/lib/server/v2-serializers.ts
@@ -1,4 +1,4 @@
-import { toHm } from '$lib/schedule-utils';
+import { blockDuration, isOvernight, toHm } from '$lib/schedule-utils';
 
 // Canonical solfeggio id <- Hz, mirroring the kiosk's `frequencyIdForHz()`
 // map (radiantwave-rebuild src/audio/audio_downloader.cpp). v2 must emit these
@@ -147,6 +147,8 @@ export type V2ScheduleBlock = {
 	startMinutes: number;
 	endTime: string;
 	endMinutes: number;
+	overnight: boolean;
+	durationMinutes: number;
 	proclamationIds: string[];
 };
 
@@ -156,7 +158,9 @@ export type V2Schedule = {
 };
 
 /** Build a schedule Block for the kiosk. Only the selected Proclamation IDs are
- * returned; the kiosk fetches proclamation content separately. */
+ * returned; the kiosk fetches proclamation content separately. `overnight`
+ * marks a range that crosses midnight (end clock time before start), and
+ * `durationMinutes` counts the wrap as the next day. */
 export function serializeScheduleBlock(
 	block: { id: string; startMinutes: number; endMinutes: number },
 	proclamationIds: string[]
@@ -167,6 +171,8 @@ export function serializeScheduleBlock(
 		startMinutes: block.startMinutes,
 		endTime: toHm(block.endMinutes),
 		endMinutes: block.endMinutes,
+		overnight: isOvernight(block),
+		durationMinutes: blockDuration(block),
 		proclamationIds
 	};
 }
diff --git a/src/routes/api/v2/schedule/schedule.spec.ts b/src/routes/api/v2/schedule/schedule.spec.ts
index 76870cc..de18046 100644
--- a/src/routes/api/v2/schedule/schedule.spec.ts
+++ b/src/routes/api/v2/schedule/schedule.spec.ts
@@ -86,7 +86,7 @@ describe('GET /api/v2/schedule auth', () => {
 });
 
 describe('GET /api/v2/schedule success', () => {
-	it('returns only proclamation IDs even when the key is inactive', async () => {
+	it('returns only proclamation IDs, marking an overnight block, even when the key is inactive', async () => {
 		licenseKeyFindUnique.mockResolvedValue({
 			key: KEY,
 			userId: 'user-1',
@@ -97,8 +97,8 @@ describe('GET /api/v2/schedule success', () => {
 		blockFindMany.mockResolvedValue([
 			{
 				id: 'block-1',
-				startMinutes: 360,
-				endMinutes: 480,
+				startMinutes: 21 * 60,
+				endMinutes: 9 * 60,
 				proclamations: [{ proclamation: { id: 'p1' } }, { proclamation: { id: 'p2' } }]
 			}
 		]);
@@ -111,10 +111,12 @@ describe('GET /api/v2/schedule success', () => {
 			blocks: [
 				{
 					id: 'block-1',
-					startTime: '06:00',
-					startMinutes: 360,
-					endTime: '08:00',
-					endMinutes: 480,
+					startTime: '21:00',
+					startMinutes: 1260,
+					endTime: '09:00',
+					endMinutes: 540,
+					overnight: true,
+					durationMinutes: 720,
 					proclamationIds: ['p1', 'p2']
 				}
 			]
@@ -134,9 +136,20 @@ describe('GET /api/v2/schedule success', () => {
 		]);
 
 		const response = await call({ email: 'jane@example.com', licenseKey: KEY });
-		const body = (await response.json()) as { blocks: { proclamationIds: string[] }[] };
+		const body = (await response.json()) as {
+			blocks: { proclamationIds: string[]; overnight: boolean; durationMinutes: number }[];
+		};
 
-		expect(body.blocks[0].proclamationIds).toEqual(['p1']);
+		expect(body.blocks[0]).toEqual({
+			id: 'block-1',
+			startTime: '00:00',
+			startMinutes: 0,
+			endTime: '01:00',
+			endMinutes: 60,
+			overnight: false,
+			durationMinutes: 60,
+			proclamationIds: ['p1']
+		});
 	});
 
 	it('accepts the legacy `key` query alias and an email-only license', async () => {