diff --git a/apps/web/cypress/e2e/layout.cy.ts b/apps/web/cypress/e2e/layout.cy.ts
index 8bd0547..0672284 100644
--- a/apps/web/cypress/e2e/layout.cy.ts
+++ b/apps/web/cypress/e2e/layout.cy.ts
@@ -283,6 +283,13 @@ describe("Responsive breakpoint — page content under 640px (issue #39)", () =>
   // *that* switch; the day view's own day-by-day content is
   // PlanningPage.tsx's own spec (planning-page.cy.ts).
   it("shows the one-day mobile view instead of the horizontally-scrolling grid, on a phone", () => {
+    // `PlanningDayView` opens on *today's* weekday within the shown week
+    // (`defaultDayIndexForWeek`, derived from `Date`). Freeze "today" to a
+    // Monday so it opens on "lundi" — where the mocked recipe below is —
+    // instead of drifting with the real date (this test used to pass only
+    // when CI happened to run on a Monday, UTC). `["Date"]` only, so
+    // timers/debounces still run.
+    cy.clock(new Date("2026-08-17T09:00:00.000Z"), ["Date"]);
     cy.intercept("GET", /\/planning\?/, {
       statusCode: 200,
       body: {