Welcome to Android Central! What calendar account were you using? The best one to use is your Google Calendar account, because that will sync automatically and immediately with your Google Calendar in the cloud. If the events were saved to your Samsung account, then they would have been backed up to your Samsung account in the cloud, assuming you had that set up. But if the events were only saved to the local Phone account, then they most likely weren't backed up anywhere, since that account doesn't sync with anything.