There is caring about outcomes and then there is caring about outcomes but being less concerned about them. This week I am in the latter camp. I still care, because I'm there, but what transpires has less of an effect upon me because I'm at work six days this week instead of five. And I have to survive. Physically, mentally.
I have worked a lot of overtime in my day and the best way to get through it is to take it day by day and not think about things so much. Institued by my past experience almost automatically for my protection, detachment in this way is sort of a fatalistic acceptance, but the quality of detachment from any situation can also be generated by simply making the mental effort to do so, a method that I have learned and shall employ to bolster me further. In other words yes, there is an inevitability when it comes to working overtime, you KNOW that you will be there, which makes detachment necessary to generate, but detachment can also be automatically fostered by other conditions.
Feeling sick can cause detachment, experiencing an unusual day-long mental state that comes from who knows where or why and lasts all day, or being preoccupied with some other matter to the point where it's hard to keep attention on your job. Then, even beyond those quite ordinary and commonplace states of being there is the spiritual quality of detachment I alluded to earlier, which is a state generated purposely. An intent is made to view the day as an observer and not a participant, even though you are participating. This is easily done, all it takes is a little focus. Anybody can do it but so few do. Look around you this day and see how many are detached from the situation at hand, it's probably not many. People get so caught up in the day to day!
Detachment, learning how to do it purposely, is a spiritual tool in your tool kit that you can learn to use. Try lessening your self-importance for a day or two (or more). You will experience noticable stress reduction and a greater sense of peace with whatever is transpiring.