Sir Alex Ferguson had a rocky start to his United career, but the club famously stuck by him to their great benefit.
But asked if he can hope for the same level of patience Ferguson received, Moyes said: "Probably not.
"I don't think in this day and age you would get that. I don't think you can ever ask for time now.
"All you can ask is to be judged on how it goes. I don't think time is something managers tend to get. It is a tough start."