Reminders
In the iPhone and Android apps you can get a reminder about an event at 9am the day before. (The web version doesn't send reminders.)
Set a reminder
Tap the bell on the event. Tap it again to turn the reminder off.
The bell disappears at 11pm the night before an event, when it's too late for a reminder.
When an event changes
If an event's date, time or place changes, your reminder moves with it, and the event shows Reminder updated for a short time. If an event is deleted, its reminder is cancelled.
See your reminders
Open the ☰ menu and tap Pending Notifications to see every reminder you've set. Tap the bin next to one to remove it.