Seriously, we all need time off, and not just time off of work. We need to take breaks from everything in life to gain the perspectives necessary to have a balanced life. When things become repetitive, our lives become boring and our actions definitely demonstrate this as a fact. You will have people who are angry all the time, and really insane. They become complacent. Their actions are the actions of a person who is unhappy. Some people try to divert the fact that that person is unhappy by implying that they need to "get some." I am sorry but sex doesn't cure everything. Trust me if it did, our hospitals would be more like brothels than nursing homes.
So for now, try to encourage your co-worker (who is rather annoying, and brags about how much time they have banked, but the mere fact that they are at work is irritating the other staff) that for their(and your) mental health, they should use that banked time, and enjoy their time off.
So whether you need your mental health day, your well-needed vacation, or just some time to relax, every once in a while, take a day off of work (life).
:o) I am off for the next seven days...Yay!