Are you sure you're receiving a cable signal? (Does live TV work)?
What receiver do you have? Identifying Your Cox Digital Receiver
Are you sure the model receiver you have includes a clock display?
Cox TV has 'Front Panel Display Options' > Time Always | Channel Always | Channel When Tuning Does Contour have a similar setting that would need to be set to 'Time Always'?
Does the clock not display after rebooting the receiver?
Try Resetting Your Cable Receiver
If the model receiver you have includes a clock display that doesn't show time with the proper Contour setting after rebooting and resetting, you could have a defective cable receiver. Based upon your assertion that "the majority of the lights in the clock display are Not working, even after playing with the brightness", my guess is the box may function for viewing and recording, but the clock display will probably never work.