Hi...my longest fast was 18 days distilled water only, about two years ago.
Since then I have fasted for 10 days numerous times.
My last 10 day fast was over the summer.
So I'm going again...hopefully for longer then 10 days as my 18 day was incredibly healing.
I am fortunate that I don't have to work, but my very first 10 day fast was when I was working full time! Yes, it was difficult...it's much easier to rest and fast, and better for you. But if you really want it, you can work and fast. Just be cautious driving, as I experienced blackouts on my first longish fast. At work too...
Tho I haven't blacked out since then while fasting. :-)