Water fasting and working can be rough, especially if you are dealing with a lot of detox. I actually scheduled my vacation to do a ten day water fast. I did this a couple of years ago and made nine days with little trouble. My mistake was telling my doctor I had been fasting for nine days. He freaked out and had me end the fast. Now I feel a need to fast again an I am going to follow my instincts with no appointments scheduled during the time. I am preparing to transition to Water Fasting by doing a liquid diet (juices and green "superfood" drinks) for a couple of weeks. I find this to be even harder than water fasting, but I know I need to do some slower cleansing and a Liver Flush to get properly prepared.
Water fasting can be done while working, but it can also be stressful on the body. If you feel you are going downhill then consider switching to a juice fast or nutrition dense liquid diet for every day and Water Fast when you can rest. You will still reap many benefits, but at a slower rate.