Frequency of backups
How often you make backups will depend on the type of data to be backed up. For example, if you are running a network environment with critical data stored on your servers, then even nightly backups may not be enough.
On the other hand, if you are backing up the data on your home computer then hourly backups would likely be unnecessary. You may find it helpful to consider the following points when planning your backup schedule:
The amount of time you spend on the computer.
How often and by how much the data on the computer changes.
If the data you want to back up is lower priority, or subject to few changes, like music, e-mails and family photos, then weekly or even monthly backups may suffice. However, if you happen to be in the middle of a tax audit, more frequent backups may be necessary.
As a general rule, the amount of time in between backups should be no more than the amount of time you are willing to spend re-doing any lost work. For example, if spending a week re-writing lost documents is too long for you, you should back up at least once per week.