No need to worry about data loss with Intervals web-based project management. Database backups are kept in real-time at the data center. A nightly backup is taken offsite and stored in a secure facility with monthly retention. As for documents, they are backed up as well, but only as long as the document exists on our primary servers. If the document is deleted from Intervals, it is deleted from the backup a few hours later.
Additional information about our security and backups can be found in our security page.