Azure Disk Backup offers multiple backups per day. If you require more frequent backups, choose the Hourly backup frequency. The backups are scheduled based on the Time interval selected. For example, if you select Every 4 hours, then the backups are taken at approximately every 4 hours so that the backups are distributed equally across the day. If once a day backup is sufficient enough, then choose the Daily backup frequency. In the daily backup frequency, you can specify the time of the day when your backups will be taken. It's important to note that the time of the day indicates the backup start time and not the time when the backup completes. The time required to complete the backup operation is dependent on various factors including the churn rate between consecutive backups. However, Azure Disk backup is an agentless backup that uses incremental snapshots that don't impact the production application performance.