Corrected entry: Just what time does Henry Winkler go to work, anyway? There's an implication he goes in at about 6pm, because we see him going into the subway while everyone else is coming out during the afternoon rush. If that's the case, he should get out of work sometime in the middle of the night. But when we see him coming home, it's already daylight. That means he would work a 14 hour day. That's unlikely for a city worker.
Corrected entry: In one scene, you see Henry Winkler's neighbour cracking some eggs into a frying pan and making fried eggs. When she serves the eggs, they are scrambled.
Correction: She scrambles them in the pan. You can see her shadow on the wall scrambling them when the shot switches to Henry Winkler.
Correction: Not necessarily. There are a number of variables that could effect this scenario that are unknown to the viewer. The first is addressed by yourself, exact time he leaves for work. Second, length of commute. Third, time of year which affects exact hours of daylight. Fourth, exactly what the character does on his way to work, we know he stops and gets a paper and reads it leisurely as he walks, maybe he also stops and gets something to eat. Fifth, the exact length of the afternoon rush hour in New York City in 1982. There are simply too many unknowns to call this a true movie mistake.
OneHappyHusky