diff --git a/packages/api/src/.internal-tests/eastern-day.test.ts b/packages/api/src/.internal-tests/eastern-day.test.ts
new file mode 100644
index 00000000..add08e98
--- /dev/null
+++ b/packages/api/src/.internal-tests/eastern-day.test.ts
@@ -0,0 +1,17 @@
+import { describe, expect, it } from "vitest";
+import { startOfEasternDay } from "../routers/admin";
+
+describe("startOfEasternDay", () => {
+  it.each([
+    // Evening in Atlanta is already tomorrow in UTC; today still began at
+    // Eastern midnight.
+    ["2026-09-25T00:30:00Z", "2026-09-24T04:00:00.000Z"],
+    ["2026-12-25T03:00:00Z", "2026-12-24T05:00:00.000Z"],
+    // The DST days: midnight is before the 2am switch, so it keeps the
+    // offset the day started with.
+    ["2026-03-08T20:00:00Z", "2026-03-08T05:00:00.000Z"],
+    ["2026-11-01T20:00:00Z", "2026-11-01T04:00:00.000Z"],
+  ])("%s starts its Eastern day at %s", (now, expected) => {
+    expect(startOfEasternDay(new Date(now)).toISOString()).toBe(expected);
+  });
+});
diff --git a/packages/api/src/.internal-tests/qr-checkin.test.ts b/packages/api/src/.internal-tests/qr-checkin.test.ts
index 26d2dac5..5f4ddf18 100644
--- a/packages/api/src/.internal-tests/qr-checkin.test.ts
+++ b/packages/api/src/.internal-tests/qr-checkin.test.ts
@@ -377,6 +377,51 @@ describe("QR check-in", () => {
         expect(mockInsert).toHaveBeenCalled();
       });
 
+      // The session's own term decides, not the day it falls on.
+      it("admits a member enrolled for the session's own term", async () => {
+        mockFindFirst.mockImplementation((table: string) => {
+          if (table === "events")
+            return clubEvent({
+              bootcampOnly: true,
+              bootcampWeek: 3,
+              bootcampTerm: "2031-spring",
+            });
+          if (table === "members")
+            return { ...activeMember, bootcampTerm: "2031-spring" };
+          return undefined;
+        });
+        mockUpdate.mockReturnValue([{ id: CLUB_EVENT }]);
+        mockInsert.mockReturnValue([{ id: "checkin_1" }]);
+
+        const caller = appRouter.createCaller(createMockCtx("member_user"));
+
+        await expect(
+          caller.events.checkIn({ qrCode: QR_OLD }),
+        ).resolves.toMatchObject({ success: true });
+      });
+
+      it("turns away a current-term member from another term's session", async () => {
+        mockFindFirst.mockImplementation((table: string) => {
+          if (table === "events")
+            return clubEvent({
+              bootcampOnly: true,
+              bootcampWeek: 3,
+              bootcampTerm: "2031-spring",
+            });
+          if (table === "members")
+            return { ...activeMember, bootcampTerm: currentTerm() };
+          return undefined;
+        });
+
+        const caller = appRouter.createCaller(createMockCtx("member_user"));
+        const err: any = await caller.events
+          .checkIn({ qrCode: QR_OLD })
+          .catch((e: unknown) => e);
+
+        expect(err.code).toBe("FORBIDDEN");
+        expect(mockInsert).not.toHaveBeenCalled();
+      });
+
       it("still refuses a second scan of the same badge", async () => {
         mockFindFirst.mockImplementation((table: string) => {
           if (table === "events") return bootcampSession();
diff --git a/packages/api/src/routers/admin.ts b/packages/api/src/routers/admin.ts
index 0bee00d2..e0aac57c 100644
--- a/packages/api/src/routers/admin.ts
+++ b/packages/api/src/routers/admin.ts
@@ -18,6 +18,38 @@ import { compareTerms, currentTerm } from "@query/db/services/membership";
 import { isExpiredAdmin, isStaffRole } from "../types/portal-context";
 import type { DrizzleDB } from "@query/db";
 
+const easternDate = new Intl.DateTimeFormat("en-CA", {
+  timeZone: "America/New_York",
+  year: "numeric",
+  month: "2-digit",
+  day: "2-digit",
+});
+const easternHour = new Intl.DateTimeFormat("en-US", {
+  timeZone: "America/New_York",
+  hour: "numeric",
+  hourCycle: "h23",
+});
+
+/**
+ * The instant Atlanta's current day began. Found by trying both Eastern
+ * offsets for today's date and keeping the one that reads 00:00 there, so it
+ * holds on the 23- and 25-hour days around a DST change too (the switch is at
+ * 2am, so midnight itself always exists exactly once).
+ */
+export function startOfEasternDay(now: Date): Date {
+  const ymd = easternDate.format(now);
+  const candidates = ["-04:00", "-05:00"].map(
+    (offset) => new Date(`${ymd}T00:00:00${offset}`),
+  );
+  return (
+    candidates.find(
+      (candidate) =>
+        easternDate.format(candidate) === ymd &&
+        Number(easternHour.format(candidate)) === 0,
+    ) ?? candidates[1]!
+  );
+}
+
 export const adminRouter = createTRPCRouter({
   isAdmin: protectedProcedure.query(async ({ ctx }) => {
     if (!ctx.userId) {
@@ -80,8 +112,10 @@ export const adminRouter = createTRPCRouter({
     }>(
       cacheKey,
       async () => {
-        const startOfToday = new Date();
-        startOfToday.setHours(0, 0, 0, 0);
+        // Midnight in Atlanta, not on the server: App Hosting runs in UTC, so
+        // "today" used to roll over at 8pm Eastern, mid-way through evening
+        // events.
+        const startOfToday = startOfEasternDay(new Date());
 
         const [
           participantsResult,
diff --git a/packages/api/src/routers/events.ts b/packages/api/src/routers/events.ts
index eba32d17..97d9dd55 100644
--- a/packages/api/src/routers/events.ts
+++ b/packages/api/src/routers/events.ts
@@ -390,8 +390,11 @@ export const eventRouter = createTRPCRouter({
           }
 
           // Bought per semester, so last term's seat is not this term's. Officers can
-          // still check somebody in by hand.
-          if (event.bootcampOnly && member?.bootcampTerm !== currentTerm()) {
+          // still check somebody in by hand. Measured against the session's own
+          // term (upsertSession stamps it), not the wall clock, so the answer
+          // cannot change with the day a session happens to fall on.
+          const sessionTerm = event.bootcampTerm ?? currentTerm();
+          if (event.bootcampOnly && member?.bootcampTerm !== sessionTerm) {
             throw new TRPCError({
               code: "FORBIDDEN",
               message: "This session is for bootcamp members this semester",