yes, but.. A day is 24 hours..not just the daylight hours.. so Friday night, is that part of Friday that is not during daylight hours..
a day is a 24 hour period, daytime-- is that portion of the day that has sunlight, night(time) is the portion with out sun. and for those of us in more northen latitudes, there is dawn and twilight.. fairly short in NY, but a wonderful time further north..eh, bean?