diff --git a/src/addons/calendar/pages/event/event.html b/src/addons/calendar/pages/event/event.html
index bcdd07a0e..2719ab3c4 100644
--- a/src/addons/calendar/pages/event/event.html
+++ b/src/addons/calendar/pages/event/event.html
@@ -140,7 +140,7 @@
                         <p>{{ reminder.label }}</p>
                     </ion-label>
                     <ion-button fill="clear" (click)="cancelNotification(reminder.id, $event)" [attr.aria-label]="'core.delete' | translate"
-                        slot="end" *ngIf="reminder.timestamp > currentTime">
+                        slot="end">
                         <ion-icon name="fas-trash" color="danger" slot="icon-only" aria-hidden="true"></ion-icon>
                     </ion-button>
                 </ion-item>
diff --git a/src/addons/calendar/services/database/calendar.ts b/src/addons/calendar/services/database/calendar.ts
index c7591fa5c..a8cc4db50 100644
--- a/src/addons/calendar/services/database/calendar.ts
+++ b/src/addons/calendar/services/database/calendar.ts
@@ -248,7 +248,8 @@ export const CALENDAR_SITE_SCHEMA: CoreSiteSchema = {
 
                     return;
                 } else {
-                    record.time = events[record.eventid].timestart - record.time;
+                    // Remove seconds from the old reminder, it could include seconds by mistake.
+                    record.time = events[record.eventid].timestart - Math.floor(record.time / 60) * 60;
                 }
 
                 return db.insertRecord(REMINDERS_TABLE, record);