I also commute to FiDi and I think the other user's schedule is very optimistic. It takes me about 1h45m. 10m to the train station by bus from Waterside, 1h train ride (people will reference the 50 minute train which is the shortest one but in the morning the trains are 55-65m), 15m subway to Fulton St., 5-10 walk to the office. And keep in mind you'll need a few minutes buffer/waiting in between every part of the trip. It takes a good 5 minutes just to get from the Metro North track to the subway track at Grand Central.