diff --git a/frontend/src/pages/HostDetailPage.tsx b/frontend/src/pages/HostDetailPage.tsx
index 3c274d6..fa20541 100644
--- a/frontend/src/pages/HostDetailPage.tsx
+++ b/frontend/src/pages/HostDetailPage.tsx
@@ -64,11 +64,11 @@ function scheduleDescription(w: MaintenanceWindow): string {
     case 'daily':
       return `Every day at ${time} for ${dur}`
     case 'weekly': {
-      const day = w.recurrence_day !== null ? DAY_NAMES[w.recurrence_day] ?? `Day ${w.recurrence_day}` : '?'
+      const day = w.recurrence_day != null ? DAY_NAMES[w.recurrence_day] ?? `Day ${w.recurrence_day}` : '?'
       return `Every ${day} at ${time} for ${dur}`
     }
     case 'monthly': {
-      const day = w.recurrence_day !== null ? w.recurrence_day : '?'
+      const day = w.recurrence_day != null ? w.recurrence_day : '?'
       return `Monthly on day ${day} at ${time} for ${dur}`
     }
   }
diff --git a/frontend/src/pages/MaintenanceWindowsPage.tsx b/frontend/src/pages/MaintenanceWindowsPage.tsx
index ac4af3c..2f59041 100644
--- a/frontend/src/pages/MaintenanceWindowsPage.tsx
+++ b/frontend/src/pages/MaintenanceWindowsPage.tsx
@@ -81,11 +81,11 @@ function scheduleDescription(w: MaintenanceWindow): string {
     case 'daily':
       return `Every day at ${time} for ${dur}`
     case 'weekly': {
-      const day = w.recurrence_day !== null ? DAY_NAMES[w.recurrence_day] ?? `Day ${w.recurrence_day}` : '?'
+      const day = w.recurrence_day != null ? DAY_NAMES[w.recurrence_day] ?? `Day ${w.recurrence_day}` : '?'
       return `Every ${day} at ${time} for ${dur}`
     }
     case 'monthly': {
-      const day = w.recurrence_day !== null ? w.recurrence_day : '?'
+      const day = w.recurrence_day != null ? w.recurrence_day : '?'
       return `Monthly on day ${day} at ${time} for ${dur}`
     }
   }