For my 1/72 scale Armor, it takes me about two to three days building two to five hours a day.
My 1/72 scale Aircraft take me about three to five days.
I take about threee weeks to build my warships, and my commercial ships (Queen Mary, Titanic, Canberra) about two to three months.
But then, I usually build about 7 to 10 kits at a time.