Working and fasting don't really go well together. Im on my 20 day right now and I cant imagine myself working, because at times you get REALLY tired. Tired to the point where all you wanna do is lay in bed and stay there the whole day. Maybe if you have an office job or if you dont have to move around that much I guess it would be possible, but when you fast you have to take so many things into consideration.
Bad Breath, Body Odor , that sickness feeling in your stomach, lightheadedness, tiredness, mood swings.
You really have to ask yourself if you will be able to socialize/work while fasting.
I encourage you to fast, just be prepared for whats coming. People dont usually know what to expect and thats why they end up "failing"