Fish do not need to eat every day. In the wild they can go a long time with no food. The fish in our tanks are the same. Just remember that the more you feed them the more they will eat and the more they will poop. That means more clean up for you. If this tank is in your office I assume at work, then you may not have a lot of time to always clean the tank. Of course some tank cleaning is a must but if I were you I would probably feed on Monday, Wednesday, and Friday once a day and only what you know they will eat. They do not need food over the week-end. I have left my fish for an entire week when I am on vacation and the fish are fine. They will appreciate clean water as opposed to more food.
Hope this helps.
Marinemom