On a Linux workstation in Lindley Hall, how can I retrieve files I accidentally deleted?

The Computer Science Department at Indiana University Bloomington owns and maintains the Linux workstations in Lindley Hall, and is responsible for nightly backups. To request a file retrieval, post to the CS Department CSG Help Desk specifying the directory path and filename to be recovered, the date the file was created or last modified, and the time the file was deleted.